Method for composite delamination

ABSTRACT

The invention provides a method for delaminating a composite by immersing the composite into a delamination solution; wherein the composite comprises a metal substrate and a coating applied on one side or both sides of the metal substrate, wherein the coating comprises a polymeric binder; and wherein the polymeric binder comprises an aqueous copolymer. The use of delamination solution comprising a strong base allows for complete delamination of the composite in a highly efficient and extremely fast manner. Furthermore, the delamination method disclosed herein circumvents complex separation processes, contamination and corrosion of the metal substrate and enables an excellent materials recovery. An application of the method for delaminating an electrode for a battery is disclosed herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage application of the International PatentApplication No. PCT/CN2021/080681, filed Mar. 15, 2021, which claims thebenefit under 35 U.S.C. § 365(c) of International Patent Application No.PCT/CN2020/096672, filed Jun. 17, 2020, International Patent ApplicationNo. PCT/CN2020/110065, filed Aug. 19, 2020 and International PatentApplication No. PCT/CN2020/117789, filed Sep. 25, 2020, the content ofall of which are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to the field of methods of materialsrecycling. In particular, this invention relates to a method ofdelamination of a composite comprising a metal substrate and a coatingapplied on one side or both sides of the metal substrate.

BACKGROUND OF THE INVENTION

The increasing urbanization, rapid development of technologicalinnovations and consequent frequent replacement of products or disposalof waste consumables have resulted in shorter lifespans for productsand/or over-production of waste. With the emergence of the growingproblems associated with waste over-generation such as detrimentaleffects on human health, adverse environmental impacts and resourcedepletion, there has been an urge in taking prompt actions to resolvethese complications worldwide using various means of waste materialprocessing.

Recycling, being a key component in waste reduction hierarchy, aims torecover invaluable materials from waste for reuse. Recycling ofmaterials brings about conservation of natural resources, reduction inenergy consumption (and hence, production costs) associated withextraction of raw materials and alleviates environmental impacts byreducing greenhouse gases and SO_(x)emissions. Owing to the substantialbenefits that materials recycling has to offer, developing highlyefficient methods to recycle materials is of utmost importance inachieving a circular economy.

The term “composite” refers to a metal substrate with a coating appliedon one side or both sides of the metal substrate, wherein the coatingcomprises a polymeric binder. The polymeric binder is responsible forthe adhesion between the coating and the metal substrate.

Application of a coating on a metal substrate is a method for alteringsurface properties to meet performance requirements in a variety oftechnical applications. Some applications of coatings include adhesives,barrier formation, scratch and abrasion resistance, chemical resistance,wettability, and biocompatibility. Coating on a metal substrate has beenfrequently adopted in battery manufacturing, membrane technology,packaging materials, printed circuit boards, wirings or cables, andbiomedical applications. Separation of coating from the metal substrateis then a technique that is heavily involved in materials recycling.

However, for products having reached their end-of-life, or with productrejects during the manufacturing process which are ready for immediaterecycling, undergoing the step of separation of the composites containedwithin the products into coating and metal substrate during recyclingpresent several difficulties.

In one respect, the delamination of the composite might occur within thebulk of the coating, rather than at the coating-metal substrateinterface. The coating may then not be fully delaminated from the metalsubstrate, with parts of coating remaining intact on the metalsubstrate. This would give rise to an undesirable loss of coatingmaterials unable to be recovered directly through the delaminationprocess, and a reclaimed metal substrate with high levels of impuritiesdue to presence of remaining coating that requires introduction ofsubsequent separation processes.

In another respect, delamination of the coating from the metal substratemight be highly inefficient, taking up to several hours. Exposing thecomposite to drastic delamination conditions for a sustained period oftime is likely to cause side effects such as corrosion, dissolution anddamage of materials within the composite, particularly the metalsubstrate, and generation of side reaction products.

Commonly used polymeric binders responsible for coating-metal substrateadhesion, such as polyvinylidene fluoride (PVDF), have their downsides,being their insolubility in water, and indeed these polymers can onlydissolve in some specific organic solvents such asN-methyl-2-pyrrolidone (NMP). NMP is flammable and toxic, and hencerequires specific handling. An NMP recovery system must be in placeduring the drying process to recover NMP vapors. This will generatesignificant costs in the manufacturing process since a large capitalinvestment would be required to set up such a recovery system.Therefore, for applications where exposure to moisture in themanufacturing process is not a significant concern, the use of polymericbinders that utilizes less expensive and more environmentally-friendlysolvents, such as aqueous solvents, most commonly water, are preferredin the present invention since it can reduce the large capital cost ofthe recovery system.

Polymeric binders that are suitable for use in water-based coatingsexhibit superior dispersion and stability in water, and are capable ofpromoting an exceptionally strong coating-metal substrate adhesion.However, it is precisely the exceptionally strong coating-metalsubstrate adhesion when these polymeric binders are used with which anexceptional challenge in the delamination of water-based coating fromtheir associated metal substrates is posed. To better optimize theproperties of these water-based binders, copolymers comprisingstructural units derived from various different monomers have beenadopted, but these copolymeric binders when used in coatings would stillpresent considerable challenges in delamination.

Delamination of composite is achieved via bond disruption and/orbreakage between the polymeric binder within the coating, and the metalsubstrate at the coating-metal substrate interface. Accordingly, it is acrucial aim to more efficiently break and/or disrupt such bonds betweenthe polymeric binder within the coating, and the metal substrate inorder for delamination to occur with high speed, high recovery rate,high safety but low quantity of additional materials used and low costsrequired.

Attempts have been made in developing methods in attaining completedelamination of composites. KR Patent Application Publication No.20130099568 A discloses a method for separating a composite comprising apolymer film coated on a metal surface by carbonizing the polymer usingelectromagnetic induction. The metal-polymer composite is firstsubjected to a step of pre-treatment wherein the polymer-metal compositeis charged in an induction furnace so as to receive the maximuminfluence of magnetic density per unit area during induction heating,making the movement of electrons on the metal surface more active.Through induction heating, the metal-polymer composite is then heated upto 500-900° C., which weakens the binding force between the polymer andthe metal surface and subsequently induces the thermal decomposition andcarbonization of the polymer coated on the metal surface, allowing foreasy separation. This method offers significant energy savings byemploying induction heating. However, this proposed method brings aboutthe carbonization of the polymer where reclamation of the polymer is notpossible. Furthermore, hazardous or toxic pollutants might be producedin the process of polymer decomposition.

In view of the above-mentioned challenges, there is always a need todevelop a unified and simple method to achieve highly efficient andcomplete delamination of composite at the coating-metal substrateinterface, wherein the coating of the composite comprises a polymericbinder, and wherein the polymeric binder is a copolymer. The method fordelamination of composite disclosed herein is developed to achieveefficient bond disruption and/or breakage between the copolymeric binderin the coating of the composite and the metal substrate. Accordingly, adelamination method that fulfills these qualities is applicable tocomposites comprising a copolymeric binder. Such a method wouldcircumvent both complex separation processes and contamination of metalsubstrate, enable excellent material recovery rates, and allow thedelamination of composite to be accomplished within a short time frame.

SUMMARY OF THE INVENTION

The aforementioned needs are met by various aspects and embodimentsdisclosed herein. In one aspect, provided herein is a method fordelaminating a composite by immersing the composite into a delaminationsolution; wherein the composite comprises a metal substrate and acoating applied on one side or both sides of the metal substrate,wherein the coating comprises a copolymeric binder.

In some embodiments, the metal substrate is selected from the groupconsisting of stainless steel, titanium, nickel, aluminum, copper,platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin,vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.

In some embodiments, the delamination solution comprises a delaminationagent and an aqueous solvent.

In some embodiments, the delamination agent is a base. In someembodiments, the base is selected from the group consisting of lithiumhydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide,cesium hydroxide, calcium hydroxide, strontium hydroxide, bariumhydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide,cesium oxide, calcium oxide, strontium oxide, barium oxide, andcombinations thereof.

Delamination of a composite attained using the method provided herein isvery rapid and simple, and does not incur a penalty in terms of loss inirrecoverable coating materials, damage in the coating materials, or theintroduction of impurities in metal substrates.

In another aspect, as one of the applications of the present invention,the aforementioned method is employed in delaminating a batteryelectrode, wherein the composite is a battery electrode, the metalsubstrate is a current collector and the coating is an electrode layer.Provided herein is a method for delaminating a battery electrode byimmersing the electrode into a delamination solution; wherein theelectrode comprises a current collector and an electrode layer coated onone side or both sides of the current collector, wherein the electrodelayer comprises a copolymeric binder.

The simple utilization of a delamination solution in the presentinvention to delaminate a battery electrode at the electrodelayer-current collector interface can drastically shorten the time takento achieve complete delamination, maximize the recovery of invaluablematerials, eliminate contamination of the current collector, and doesnot require the need for subsequent downstream processing. Furthermore,the method disclosed herein is found to be applicable to thedelamination of both cathodes and anodes without presenting corrosionconcerns to the current collector and/or electrode active materialswithin the electrode layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a simplified view of an embodiment of a composite.

FIG. 2 illustrates a schematic of the proposed coating-metal substrateinterfacial structure of a composite.

FIG. 3 is a flow chart of an embodiment illustrating the steps fordelaminating a composite as disclosed herein and its subsequent furtherprocessing for extraction of the composite constituents, namely coatingand metal substrate, following the delamination of the composite.

FIG. 4 depicts the recovered cathode layers and current collector ofExample 4 after the immersion of the double side-coated cathode into thedelamination solution, wherein the delamination solution comprisessodium hydroxide at 1 M and de-ionized water (DI water), and wherein thedouble side-coated cathode comprises a copolymeric binder.

FIG. 5 depicts the recovered cathode of Comparative Example 1, whereinthe delamination solution comprises sodium hydroxide at 0.5 M and DIwater, and wherein the double side-coated cathode comprisespolyvinylidene fluoride (PVDF) as the polymeric binder.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, provided herein is a method for delaminating a compositeby immersing the composite into a delamination solution; wherein thecomposite comprises a metal substrate and a coating applied on one sideor both sides of the metal substrate, wherein the coating comprises acopolymeric binder.

In another aspect, provided herein is a method for delaminating alithium-ion battery electrode by immersing the electrode into adelamination solution; wherein the electrode comprises a currentcollector and an electrode layer coated on one side or both sides of thecurrent collector, wherein the electrode layer comprises a copolymericbinder.

The term “electrode” refers to a “cathode” or an “anode.”

The term “positive electrode” is used interchangeably with cathode.Likewise, the term “negative electrode” is used interchangeably withanode.

The term “binder” or “binder material” refers to a chemical compound,mixture of compounds, or polymer that is used to hold material(s) inplace and adhere them onto a conductive metal substrate to form acomposite. In some embodiments, the binder refers to a chemicalcompound, mixture of compounds, or polymer that is used to hold anelectrode material and/or a conductive agent in place and adhere themonto a conductive metal part to form an electrode. In some embodiments,the electrode does not comprise any conductive agent.

The term “conductive agent” refers to a material that has goodelectrical conductivity. Therefore, the conductive agent is often mixedwith an electrode active material at the time of forming an electrode toimprove electrical conductivity of the electrode. In some embodiments,the conductive agent is chemically active. In some embodiments, theconductive agent is chemically inactive.

The term “composite” refers to a metal substrate with a coating appliedon one side or both sides of the metal substrate, wherein the metalsubstrate and the coating can each comprise one or more layers. The term“constituents” in the context of a composite refers to the metalsubstrate and the coating.

The term “polymer” refers to a compound prepared by polymerizingmonomers, whether of the same or a different type. The generic term“polymer” embraces the terms “homopolymer” as well as “copolymer”.

The term “aqueous polymer” refers to a polymer that can be dispersed inan aqueous solvent such as water to form a solution or a colloidalsystem, wherein the polymer in the colloidal system does not readilyself-aggregate.

The term “homopolymer” refers to a polymer prepared by thepolymerization of the same type of monomer.

The term “copolymer” refers to a polymer prepared by the polymerizationof two or more different types of monomers.

The term “polymeric binder” refers to a binder that is of a polymericnature. The term “copolymeric binder” then refers to a polymeric binderwherein the binder is specifically a copolymer.

The term “unsaturated” as used herein, refers to a moiety having one ormore units of unsaturation.

The term “alkyl” or “alkyl group” refers to a univalent group having thegeneral formula C_(n)H_(2n+1) derived from removing a hydrogen atom froma saturated, unbranched or branched aliphatic hydrocarbon, where n is aninteger, or an integer between 1 and 20, or between 1 and 8. Examples ofalkyl groups include, but are not limited to, (C₁-C₈)alkyl groups, suchas methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl,2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl,2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl,4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl,4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl,2-ethyl-1-butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl,hexyl, heptyl, and octyl. Longer alkyl groups include nonyl and decylgroups. An alkyl group can be unsubstituted or substituted with one ormore suitable substituents. Furthermore, the alkyl group can be branchedor unbranched. In some embodiments, the alkyl group contains at least 2,3, 4, 5, 6, 7, or 8 carbon atoms.

The term “cycloalkyl” or “cycloalkyl group” refers to a saturated orunsaturated cyclic non-aromatic hydrocarbon radical having a single ringor multiple condensed rings.

Examples of cycloalkyl groups include, but are not limited to,(C₃-C₇)cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, and cycloheptyl, and saturated cyclic and bicyclic terpenesand (C₃-C₇)cycloalkenyl groups, such as cyclopropenyl, cyclobutenyl,cyclopentenyl, cyclohexenyl, and cycloheptenyl, and unsaturated cyclicand bicyclic terpenes. A cycloalkyl group can be unsubstituted orsubstituted by one or two suitable substituents. Furthermore, thecycloalkyl group can be monocyclic or polycyclic. In some embodiments,the cycloalkyl group contains at least 5, 6, 7, 8, 9, or 10 carbonatoms.

The term “alkoxy” refers to an alkyl group, as previously defined,attached to the principal carbon chain through an oxygen atom. Somenon-limiting examples of the alkoxy group include methoxy, ethoxy,propoxy, butoxy, and the like. And the alkoxy defined above may besubstituted or unsubstituted, wherein the substituent may be, but is notlimited to, deuterium, hydroxy, amino, halo, cyano, alkoxy, alkyl,alkenyl, alkynyl, mercapto, nitro, and the like.

The term “alkenyl” refers to an unsaturated straight chain, branchedchain, or cyclic hydrocarbon radical that contains one or morecarbon-carbon double bonds. Examples of alkenyl groups include, but arenot limited to, ethenyl, 1-propenyl, and 2-propenyl; and which mayoptionally be substituted on one or more of the carbon atoms of theradical.

The term “aryl” or “aryl group” refers to an organic radical derivedfrom a monocyclic or polycyclic aromatic hydrocarbon by removing ahydrogen atom. Non-limiting examples of the aryl group include phenyl,naphthyl, benzyl, tolanyl, sexiphenyl, phenanthrenyl, anthracenyl,coronenyl, and tolanylphenyl. An aryl group can be unsubstituted orsubstituted with one or more suitable substituents. Furthermore, thearyl group can be monocyclic or polycyclic. In some embodiments, thearyl group contains at least 6, 7, 8, 9, or 10 carbon atoms.

The term “aliphatic” refers to a C₁ to C₃₀ alkyl group, a C₂ to C₃₀alkenyl group, a C₂ to C₃₀ alkynyl group, a C₁ to C₃₀ alkylene group, aC₂ to C₃₀ alkenylene group, or a C₂ to C₃₀ alkynylene group. In someembodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8carbon atoms.

The term “aromatic” refers to groups comprising aromatic hydrocarbonrings, optionally including heteroatoms or substituents. Examples ofsuch groups include, but are not limited to, phenyl, tolyl, biphenyl,o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl,pyrenyl, triphenylenyl, and derivatives thereof.

The term “substituted” as used to describe a compound or chemical moietyrefers to that at least one hydrogen atom of that compound or chemicalmoiety is replaced with a second chemical moiety. Examples ofsubstituents include, but are not limited to, halogen; alkyl;heteroalkyl; alkenyl; alkynyl; aryl, heteroaryl, hydroxyl; alkoxyl;amino; nitro; thiol; thioether; imine; cyano; amido; phosphonato;phosphine; carboxyl; thiocarbonyl; sulfonyl; sulfonamide; acyl; formyl;acyloxy; alkoxycarbonyl; oxo; haloalkyl (e.g., trifluoromethyl);carbocyclic cycloalkyl, which can be monocyclic or fused or non-fusedpolycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl) ora heterocycloalkyl, which can be monocyclic or fused or non-fusedpolycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl orthiazinyl); carbocyclic or heterocyclic, monocyclic or fused ornon-fused polycyclic aryl (e.g., phenyl, naphthyl, pyrrolyl, indolyl,furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl,triazolyl, tetrazolyl, pyrazolyl, pyridinyl, quinolinyl, isoquinolinyl,acridinyl, pyrazinyl, pyridazinyl, pyrimidinyl, benzimidazolyl,benzothiophenyl or benzofuranyl); amino (primary, secondary ortertiary); o-lower alkyl; o-aryl, aryl; aryl-lower alkyl; —CO₂CH₃;—CONH₂; —OCH₂CONH₂; —NH₂; —SO₂NH₂; —OCHF₂; —CF₃; —OCF₃; —NH(alkyl);—N(alkyl)₂; —NH(aryl); —N(alkyl)(aryl); —N(aryl)₂; —CHO; —CO(alkyl);—CO(aryl); —CO₂(alkyl); and —CO₂(aryl); and such moieties can also beoptionally substituted by a fused-ring structure or bridge, for example—OCH₂O-. These substituents can optionally be further substituted with asubstituent selected from such groups. All chemical groups disclosedherein can be substituted, unless it is specified otherwise.

The term “halogen” or “halo” refers to F, Cl, Br or I.

The term “monomeric unit” refers to the constitutional unit contributedby a single monomer to the structure of a polymer.

The term “structural unit” refers to the total monomeric unitscontributed by the same monomer type in a polymer.

The term “acid salt group” refers to the acid salt formed when an acidreacts with a base. In some embodiments, the proton of the acid isreplaced with a metal cation. In some embodiments, the proton of theacid is replaced with an ammonium ion.

The term “planetary mixer” refers to an equipment that can be used tomix or stir different materials for producing a homogeneous mixture,which consists of blades conducting a planetary motion within a vessel.In some embodiments, the planetary mixer comprises at least oneplanetary blade and at least one high-speed dispersion blade. Theplanetary and the high-speed dispersion blades rotate on their own axesand also rotate continuously around the vessel. The rotation speed canbe expressed in unit of rotations per minute (rpm) which refers to thenumber of rotations that a rotating body completes in one minute.

The term “ultrasonicator” refers to an equipment that can applyultrasound energy to agitate particles in a sample. Any ultrasonicatorthat can disperse the slurry disclosed herein can be used herein. Somenon-limiting examples of the ultrasonicator include an ultrasonic bath,a probe-type ultrasonicator, and an ultrasonic flow cell.

The term “ultrasonic bath” refers to an apparatus through which theultrasonic energy is transmitted via the container's wall of theultrasonic bath into the liquid sample.

The term “probe-type ultrasonicator” refers to an ultrasonic probeimmersed into a medium for direct sonication. The term “directsonication” means that the ultrasound is directly coupled into theprocessing liquid.

The term “ultrasonic flow cell” or “ultrasonic reactor chamber” refersto an apparatus through which sonication processes can be carried out ina flow-through mode. In some embodiments, the ultrasonic flow cell is ina single-pass, multiple-pass, or recirculating configuration.

The term “applying” refers to an act of laying or spreading a substanceon a surface.

The term “current collector” refers to any conductive layer which is incontact with an electrode layer, and is capable of conducting anelectrical current flowing to electrodes during discharging or charginga secondary battery. Some non-limiting examples of the current collectorinclude a single conductive metal layer or substrate, and a singleconductive metal layer or substrate with an overlying conductive coatinglayer, such as a carbon black-based coating layer. The conductive metallayer or substrate may be in the form of a foil or a porous body havinga three-dimensional network structure. In some embodiments, thethree-dimensional porous current collector is coated with a conformalcarbon layer.

The term “electrode layer” refers to a coating which is in contact witha current collector, that comprises an electrochemically activematerial. In some embodiments, the electrode layer is made by applying acoating on to the current collector. In some embodiments, the electrodelayer is located on one side or both sides of the current collector. Inother embodiments, the three-dimensional porous current collector iscoated conformally with an electrode layer. Accordingly, an electrode isa composite, where the current collector is the metal substrate, whilethe electrode layer is the coating.

The term “room temperature” refers to indoor temperatures from about 18°C. to about 30° C., e.g., 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,29, or 30° C. In some embodiments, room temperature refers to atemperature of about 20° C. +/−1° C. or +/−2° C. or +/−3° C. In otherembodiments, room temperature refers to a temperature of about 22° C. orabout 25° C.

The term “solid content” refers to the amount of non-volatile materialremaining after evaporation.

The term “peeling strength” refers to the amount of force required toseparate a current collector and an electrode active material coatingthat are bonded to each other. It is a measure of the binding strengthbetween such two materials and is usually expressed in N/cm.

The term “adhesive strength” refers to the amount of force required toseparate a current collector and a polymeric binder coating that arebonded to each other. It is a measure of the adhesion strength betweensuch two materials and is usually expressed in N/cm.

The term “C rate” refers to the charging or discharging rate of a cellor battery, expressed in terms of its total storage capacity in Ah ormAh. For example, a rate of 1 C means utilization of all of the storedenergy in one hour; a 0.1 C means utilization of 10% of the energy inone hour or full energy in 10 hours; and a 5 C means utilization of fullenergy in 12 minutes.

The term “ampere-hour (Ah)” refers to a unit used in specifying thestorage capacity of a battery. For example, a battery with 1 Ah capacitycan supply a current of one ampere for one hour or 0.5 A for two hours,etc. Therefore, 1 ampere-hour (Ah) is the equivalent of 3,600 coulombsof electrical charge. Similarly, the term “milliampere-hour (mAh)” alsorefers to a unit of the storage capacity of a battery and is 1/1,000 ofan ampere-hour.

The term “battery cycle life” refers to the number of completecharge/discharge cycles a battery can perform before its nominalcapacity falls below 80% of its initial rated capacity.

The term “capacity” is a characteristic of an electrochemical cell thatrefers to the total amount of electrical charge an electrochemical cell,such as a battery, is able to hold. Capacity is typically expressed inunits of ampere-hours. The term “specific capacity” refers to thecapacity output of an electrochemical cell, such as a battery, per unitweight, usually expressed in Ah/kg or mAh/g.

In the following description, all numbers disclosed herein areapproximate values, regardless whether the word “about” or “approximate”is used in connection therewith. They may vary by 1 percent, 2 percent,5 percent, or, sometimes, 10 to 20 percent. Whenever a numerical rangewith a lower limit, RL, and an upper limit, RU, is disclosed, any numberfalling within the range is specifically disclosed. In particular, thefollowing numbers within the range are specifically disclosed: ,R=R^(L)+k*(R^(U)−R^(L)) wherein k is a variable ranging from 0 percentto 100 percent. Moreover, any numerical range defined by two R numbersas defined in the above is also specifically disclosed.

In the present description, all references to the singular includereferences to the plural and vice versa.

A “composite” as described herein refers to a metal substrate with acoating applied on one side or both sides of the metal substrate, ofwhich the metal substrate and the coating can each comprise one or morelayers, and wherein the coating comprises a polymeric binder. In someembodiments, the polymeric binder is a copolymer, i.e. a copolymericbinder. FIG. 1 shows a simplified view of a composite, represented by100. The composite 100 comprises a metal substrate 101 with a coating102 applied on one side of the metal substrate 101. Applying a coatingon a metal substrate, i.e. formation of a composite, is one of the mostcommonly used techniques in producing an alteration in the surfacecharacteristics of the metal substrate to meeting performancerequirements for various applications. Coating has been frequentlyutilized for various purposes, including protection (e.g. againstchemicals, corrosion, scratch and abrasion, etc.), adhesion, wettabilitymodification, or biocompatibility.

Adhesion between the coating and the metal substrate within thecomposite is attained via the interactions between the polymeric bindercomprised in the coating, and the surface of the metal substrate towhich the coating is applied on. Copolymeric binders compatible withaqueous solvents, most commonly water, can strongly adhere the coatingto the metal substrate. Therefore, the incorporation of such acopolymeric binder is preferred in the present invention. Moreover,since these copolymeric binders are capable of achieving good dispersionand stability in water, water-based coatings comprising thesecopolymeric binders would hence have good processibility in formation,storage, and utilization.

In some embodiments, the substrate is a metallic substrate. In someembodiments, the substrate is selected from the group consisting ofstainless steel, titanium, nickel, aluminum, copper, platinum, gold,silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc,cadmium, iron, cobalt, lead, and alloys thereof.

Quite often, the metal substrate is exposed to ambient air for a periodof time prior to applying a coating on the surface(s) of the metalsubstrate. Ambient air contains primarily oxygen, water and severalorganic and inorganic species. Upon exposure of metal substrate tonaturally occurring oxygen in the atmosphere, it is inevitable for metaloxide to be developed on the metal substrate surface(s). For example,metallic aluminum is naturally very reactive with atmospheric oxygen,initiating the formation of aluminum oxide on the exposed aluminumsurface(s). This aluminum oxide protects the aluminum contained withinfrom undergoing further oxidation and consequently aluminum has goodcorrosion resistance. As the metal oxide on the surface of the metalsubstrate comes into contact with moisture in ambient air, hydroxylationof the metal oxide occurs, enriching the surface of the metal oxide withhydroxyl (—OH) groups.

The hydroxyl group at the metal substrate surface consists of a H atomcovalently bonded to a more electronegative O atom and anelectronegative O atom bearing a lone pair of electrons in the outmostelectron shell. Within the hydroxyl group, the hydrogen atom is capableof forming a hydrogen bond with another molecule that contains a highlyelectronegative atom such as O, N or F, and the oxygen atom is capableof accepting a hydrogen bond from a hydrogen atom of another moleculethat is similarly bonded to a highly electronegative atom such as O, Nor F.

Meanwhile, metal parts of the substrate are still present on the metalsubstrate surface are in the form of a partially positively chargedmetal species (M^(δ+)), for example in the metal oxide developed on themetal substrate surface.

FIG. 2 illustrates a schematic of the proposed coating-metal substrateinterfacial structure of a composite, represented by 200. Hydroxyl (—OH)groups, partially positively charged metal species (M^(δ+)) and oxygen(O) atoms of the metal oxide are present on the surface of the metalsubstrate 201. The copolymeric binder contained within the coating 202and/or at the surface of the coating 202 comprises structural unitsderived from a carboxylic acid group-containing monomer. The structuralunit derived from a carboxylic acid group-containing monomer in thiscase comprises a carboxylic salt group, wherein a carboxylic salt groupis a salt of a carboxylic acid group.

Oxygen (O) and hydrogen (H) atoms present in the copolymeric binder arelikely to interact with the O and/or H atoms of the hydroxyl groups andthe O atom(s) in metal oxide at the metal substrate surface via hydrogenbond formations. In addition, an ion-dipole interaction is exertedbetween the anion of the carboxylic salt group, COO- in this case andcontained within the copolymeric binder, and the M^(δ+)species at themetal substrate surface. Accordingly, hydrogen bonding and/or ion-dipoleattractions would be formed between coating and metal substrate, andthese two types of interactions contribute considerably andsignificantly to the adhesion of the coating onto the surface of themetal substrate.

The copolymeric binders disclosed herein are formulated to provide anexceptionally strong coating-metal substrate adhesion for variousapplications. However, the strong adhesion presents an added challengein the detachment of the coating from its associated metal substrate inthe subsequent recycling step as the composite-containing productreaches the end of its usefulness or lifespan or as the product rejectsare generated during production.

Delamination of the coating from the metal substrate in the composite isaccomplished via bond disruption and/or breakage between the copolymericbinder comprised in the coating, and the metal substrate surface.Copolymers of different compositions that display varying specificproperties would require different approaches to separate the coatingfrom the metal substrate. Accordingly, the method of the presentinvention is specifically developed to delaminate a composite bydisrupting and/or breaking the bonds between the aqueous copolymericbinders disclosed herein and a metal substrate surface.

The present invention provides a method for delaminating a composite byimmersing the composite into a delamination solution; wherein thecomposite comprises a metal substrate and a coating applied on one sideor both sides of the metal substrate, wherein the coating comprises acopolymeric binder.

In some embodiments, delamination of the composite occurs along thecoating-metal substrate interface.

In some embodiments, the delamination solution comprises a delaminationagent and an aqueous solvent. In some embodiments, the delaminationagent is a water-soluble strong base. In some embodiments, the aqueoussolvent consists solely of water.

Within the delamination solution, the strong base can be an alkali oralkaline earth metal oxide, an alkali or alkaline earth metal hydroxide,or combinations thereof. In the case of a hydroxide, the said strongbase dissociates in an aqueous solvent with the release of theconstituent ions within the strong base. In the case of an oxide, theoxide instead reacts with water, once again forming ions.

These ions could enter the interface between the copolymeric binder andthe metal substrate surface. The ions would disrupt the hydrogen bondingand ion-dipole interactions between the copolymeric binder and the metalsubstrate. The aqueous solvent (e.g. water) present in the delaminationsolution also brings about disruption to the ion-dipole interactionsbetween the copolymeric binder in the coating and the metal substratesurface. These aqueous solvent molecules further act to solvate thecopolymer, creating solvation shells (hydration shells in the case ofwater), which severely diminishes the strength of electrostaticinteractions between the copolymeric binder of the coating and the metalsubstrate.

In some embodiments, some functional groups within the polymer capableof dissociating in water, such as carboxylic acid groups, are notcompletely dissociated in water. The strong base would further act toneutralize the undissociated functional groups, resulting in theformation of the corresponding anion, such as the carboxylate anion whena carboxylic acid functional group is present. Attraction of water tosuch an anion, for example carboxylate, is stronger than the attractionof water to the undissociated functional group. With the ionization ofthese dissociable functional groups, the greater solvation effects ofthe ionized functional groups in water would hence result in a moreeffective reduction in interactions between polymer and metal substrate.This thus leads to coating delamination.

Therefore, the method disclosed herein of the present invention isdirected towards achieving delamination of a composite by disruptingand/or breaking the hydrogen and/or ion-dipole interactions between acoating and a metal substrate surface via the use of a delaminationsolution, wherein the coating comprises a copolymeric binder. The methodis simple and does not require the involvement of complex separationprocesses. The proposed method ensures complete delamination ofcomposite at the coating-metal substrate interface with no contaminationof metal substrate which enables exceptional materials recovery, andallows the delamination of composite to be achieved with high efficiencyand speed.

Non-ionized copolymer functional groups do not interact with the metalsubstrate surface via ion-dipole interactions. The use of aqueoussolvent alone as the delamination solution may be insufficient incompletely delaminating the coating from the metal substrate assolvation of the aqueous solvent on these non-ionized copolymerfunctional groups would be noticeably lower; and the interactions,mostly hydrogen bonding, between these copolymer functional groupswithin the coating and the metal substrate surface would often not bedisrupted and diminished to an extent where complete delamination of thecomposite is made possible.

Therefore, both delamination agent and aqueous solvent are to be used inconjunction as the delamination solution to achieve superiordelamination performance of the composite. In some embodiments, thedelamination solution comprises a delamination agent and an aqueoussolvent.

In some embodiments, the delamination agent is a strong base. In someembodiments, the delamination agent is an alkali or alkaline earth metalhydroxide. In some embodiments, the delamination agent is an alkali oralkaline earth metal oxide. In some embodiments, the delamination agentis lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidiumhydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide,barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidiumoxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, orcombinations thereof.

In some embodiments, the aqueous solvent is a solution containing wateras the major component and a volatile solvent, such as alcohols, loweraliphatic ketones, lower alkyl acetates or the like, as the minorcomponent in addition to water. In some embodiments, the proportion ofwater in the aqueous solvent is from about 51% to about 100%, from about51% to about 95%, from about 51% to about 90%, from about 51% to about85%, from about 51% to about 80%, from about 51% to about 75%, fromabout 51% to about 70%, from about 55% to about 100%, from about 55% toabout 95%, from about 55% to about 90%, from about 55% to about 85%,from about 55% to about 80%, from about 60% to about 100%, from about60% to about 95%, from about 60% to about 90%, from about 60% to about85%, from about 60% to about 80%, from about 65% to about 100%, fromabout 65% to about 95%, from about 65% to about 90%, from about 65% toabout 85%, from about 70% to about 100%, from about 70% to about 95%,from about 70% to about 90%, from about 70% to about 85%, from about 75%to about 100%, from about 75% to about 95% or from about 80% to about100% by weight.

In some embodiments, the proportion of water in the aqueous solvent ismore than 50%, more than 55%, more than 60%, more than 65%, more than70%, more than 75%, more than 80%, more than 85%, more than 90% or morethan 95% by weight. In some embodiments, the proportion of water in theaqueous solvent is less than 55%, less than 60%, less than 65%, lessthan 70%, less than 75%, less than 80%, less than 85%, less than 90% orless than 95% by weight. In some embodiments, the aqueous solventconsists solely of water, that is, the proportion of water in theaqueous solvent is 100% by weight.

Some non-limiting examples of water include tap water, bottled water,purified water, pure water, distilled water, DI water, D₂O, andcombinations thereof. In some embodiments, the aqueous solvent isde-ionized water. Water may be applied as part of the delaminationsolution to form solvation shells around the copolymeric binder of thecoating and the metal substrate surface at the coating-metal substratesurface interface. This helps to disrupt the interactions between thecopolymeric binder in the coating and the metal substrate surface andconsequently gives rise to the complete delamination of the composite.

Any water-miscible solvents or volatile solvents can be used as theminor component (i.e. solvents other than water) of the aqueous solvent.Some non-limiting examples of the water-miscible solvents or volatilesolvents include alcohols, lower aliphatic ketones, lower alkylacetates, and combinations thereof. The addition of alcohol can improvethe solubility of the delamination agent and lower the freezing point ofwater. Some non-limiting examples of the alcohol include C₁-C₄ alcohols,such as methanol, ethanol, isopropanol, n-propanol, tert-butanol,n-butanol, and combinations thereof. Some non-limiting examples of thelower aliphatic ketones include acetone, dimethyl ketone, methyl ethylketone (MEK), and combinations thereof. Some non-limiting examples ofthe lower alkyl acetates include ethyl acetate (EA), isopropyl acetate,propyl acetate, butyl acetate (BA), and combinations thereof. In someembodiments, the aqueous solvent does not comprise an alcohol, a loweraliphatic ketone, a lower alkyl acetate, or combinations thereof.

Surfactants have been used as additives to delamination solutions inorder to improve the rate of delamination. However, the addition ofsurfactants to the delamination solution would constitute impurities inthe resultant solutions, resulting in reduced product purity orotherwise requiring time and capital in developing a separation systemto remove the surfactants. In addition, surfactants are harmful to theenvironment when released, and some may additionally pose health risks.Therefore, in some embodiments, no surfactant is added to thedelamination solution. In some embodiments, the delamination solution isfree of cationic surfactant, anionic surfactant, nonionic surfactant,and amphoteric surfactant.

In some embodiments, no anionic surfactants including fatty acid salts;alkyl sulfates; polyoxyalkylene alkyl ether acetates; alkylbenzenesulfonates; polyoxyalkylene alkyl ether sulfates; higher fatty acidamide sulfonates; N-acylsarcosin salts; alkyl phosphates;polyoxyalkylene alkyl ether phosphate salts; long-chain sulfosuccinates;long-chain N-acylglutamates; polymers and copolymers comprising acrylicacids, anhydrides, esters, vinyl monomers and/or olefins and theiralkali metal, alkaline earth metal and/or ammonium salt derivatives;salts of polycarboxylic acids; formalin condensate of naphthalenesulfonic acid; alkyl naphthalene sulfonic acid; naphthalene sulfonicacid; alkyl naphthalene sulfonate; formalin condensates of acids andnaphthalene sulfonates such as their alkali metal salts, alkaline earthmetal salts, ammonium salts or amine salts; melamine sulfonic acid;alkyl melamine sulfonic acid; formalin condensate of melamine sulfonicacid; formalin condensate of alkyl melamine sulfonic acid; alkali metalsalts, alkaline earth metal salts, ammonium salts and amine salts ofmelamine sulfonates; lignin sulfonic acid; and alkali metal salts,alkaline earth metal salts, ammonium salts and amine salts of ligninsulfonates are added to the delamination solution.

In some embodiments, no cationic surfactants includingalkyltrimethylammonium salts such as stearyltrimethylammonium chloride,lauryltrimethylammonium chloride and cetyltrimethylammonium bromide;dialkyldimethylammonium salts; trialkylmethylammonium salts;tetraalkylammonium salts; alkylamine salts; benzalkonium salts;alkylpyridinium salts; and imidazolium salts are added to thedelamination solution.

In some embodiments, no nonionic surfactants including polyoxyalkyleneoxide-added alkyl ethers; polyoxyalkylene styrene phenyl ethers;polyhydric alcohols; ester compounds of monovalent fatty acid;polyoxyalkylene alkylphenyl ethers; polyoxyalkylene fatty acid ethers;polyoxyalkylene sorbitan fatty acid esters; glycerin fatty acid esters;polyoxyalkylene castor oil; polyoxyalkylene hydrogenated castor oil;polyoxyalkylene sorbitol fatty acid ester; polyglycerin fatty acidester; alkyl glycerin ether; polyoxyalkylene cholesteryl ether; alkylpolyglucoside; sucrose fatty acid ester; polyoxyalkylene alkyl amine;polyoxyethylene-polyoxypropylene block polymers; sorbitan fatty acidester; and fatty acid alkanolamides are added to the delaminationsolution.

In some embodiments, no amphoteric surfactants including 2-undecyl-N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium salt,2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt;imidazoline-based amphoteric surfactants;2-heptadecyl-N-carboxymethyl-N-hydroxyethyl imidazolium betaine,lauryldimethylaminoacetic acid betaine, alkyl betaine, amide betaine,sulfobetaine and other betaine-based amphoteric surfactants;N-laurylglycine, N-lauryl β-alanine, N-stearyl β-alanine, lauryldimethylamino oxide, oleyl dimethylamino oxide, sodium lauroylglutamate, lauryl dimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, cocamidopropyl hydroxysultaine, and2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine are added tothe delamination solution.

In some embodiments, the composite comprises a metal substrate and acoating applied on one side or both sides of the metal substrate.

In some embodiments, the coating comprises a polymeric binder. Theintention of the polymeric binder in the coating is to provide adhesionbetween the coating and the metal substrate within the composite. Insome embodiments, the polymeric binder comprises an aqueous copolymer.

In some embodiments, the copolymer comprises a structural unit (a),wherein structural unit (a) is derived from a monomer selected from thegroup consisting of carboxylic acid group-containing monomer, carboxylicacid salt group-containing monomer, sulfonic acid group-containingmonomer, sulfonic acid salt group-containing monomer, phosphonic acidgroup-containing monomer, phosphonic acid salt group-containing monomer,and combinations thereof. In some embodiments, an acid salt group is asalt of an acid group. In some embodiments, an acid saltgroup-containing monomer comprises an alkali metal cation. Examples ofan alkali metal forming the alkali metal cation include lithium, sodium,and potassium. In some embodiments, an acid salt group-containingmonomer comprises an ammonium cation. In some embodiments, structuralunit (a) may comprise a combination of a monomer containing a salt groupand a monomer containing an acid group.

In some embodiments, the carboxylic acid group-containing monomer isacrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid,cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconicacid, itaconic anhydride, tetraconic acid, or combinations thereof. Incertain embodiments, the carboxylic acid group-containing monomer is2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid,trans-2-pentenoic acid, angelic acid, tiglic acid, 3,3-dimethyl acrylicacid, 3-propyl acrylic acid, trans-2-methyl-3-ethyl acrylic acid,cis-2-methyl-3-ethyl acrylic acid, 3-isopropyl acrylic acid,trans-3-methyl-3-ethyl acrylic acid, cis-3-methyl-3-ethyl acrylic acid,2-isopropyl acrylic acid, trimethyl acrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butyl acrylic acid, 2-butyl acrylic acid, 2-pentylacrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid,3-methyl-3-propyl acrylic acid, 2-ethyl-3-propyl acrylic acid,2,3-diethyl acrylic acid, 3,3-diethyl acrylic acid, 3-methyl-3-hexylacrylic acid, 3-methyl-3-tert-butyl acrylic acid, 2-methyl-3-pentylacrylic acid, 3-methyl-3-pentyl acrylic acid, 4-methyl-2-hexenoic acid,4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butylacrylic acid, 2,3-dimethyl-3-ethyl acrylic acid, 3,3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropyl acrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid,trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylicacid, α-chloro-β-E-methoxyacrylic acid, or combinations thereof. In someembodiments, the carboxylic acid group-containing monomer is methylmaleic acid, dimethyl maleic acid, phenyl maleic acid, bromo maleicacid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid,difluoro maleic acid, nonyl hydrogen maleate, decyl hydrogen maleate,dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkylhydrogen maleate, or combinations thereof. In some embodiments, thecarboxylic acid group-containing monomer is maleic anhydride, methylmaleic anhydride, dimethyl maleic anhydride, acrylic anhydride,methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloylfluoride, methacryloyl bromide, or combinations thereof.

In some embodiments, the carboxylic acid salt group-containing monomeris acrylic acid salt, methacrylic acid salt, crotonic acid salt, 2-butylcrotonic acid salt, cinnamic acid salt, maleic acid salt, maleicanhydride salt, fumaric acid salt, itaconic acid salt, itaconicanhydride salt, tetraconic acid salt, or combinations thereof. Incertain embodiments, the carboxylic salt group-containing monomer is2-ethylacrylic acid salt, isocrotonic acid salt, cis-2-pentenoic acidsalt, trans-2-pentenoic acid salt, angelic acid salt, tiglic acid salt,3,3-dimethyl acrylic acid salt, 3-propyl acrylic acid salt,trans-2-methyl-3-ethyl acrylic acid salt, cis-2-methyl-3-ethyl acrylicacid salt, 3-isopropyl acrylic acid salt, trans-3-methyl-3-ethyl acrylicacid salt, cis-3-methyl-3-ethyl acrylic acid salt, 2-isopropyl acrylicacid salt, trimethyl acrylic acid salt, 2-methyl-3,3-diethyl acrylicacid salt, 3-butyl acrylic acid salt, 2-butyl acrylic acid salt,2-pentyl acrylic acid salt, 2-methyl-2-hexenoic acid salt,trans-3-methyl-2-hexenoic acid salt, 3-methyl-3-propyl acrylic acidsalt, 2-ethyl-3-propyl acrylic acid salt, 2,3-diethyl acrylic acid salt,3,3-diethyl acrylic acid salt, 3-methyl-3-hexyl acrylic acid salt,3-methyl-3-tert-butyl acrylic acid salt, 2-methyl-3-pentyl acrylic acidsalt, 3-methyl-3-pentyl acrylic acid salt, 4-methyl-2-hexenoic acidsalt, 4-ethyl-2-hexenoic acid salt, 3-methyl-2-ethyl-2-hexenoic acidsalt, 3-tert-butyl acrylic acid salt, 2,3-dimethyl-3-ethyl acrylic acidsalt, 3,3-dimethyl-2-ethyl acrylic acid salt, 3-methyl-3-isopropylacrylic acid salt, 2-methyl-3-isopropyl acrylic acid salt,trans-2-octenoic acid salt, cis-2-octenoic acid salt, trans-2-decenoicacid salt, a-acetoxyacrylic acid salt, 3-trans-aryloxyacrylic acid salt,α-chloro-β-E-methoxyacrylic acid salt, or combinations thereof. In someembodiments, the carboxylic salt group-containing monomer is methylmaleic acid salt, dimethyl maleic acid salt, phenyl maleic acid salt,bromo maleic acid salt, chloromaleic acid salt, dichloromaleic acidsalt, fluoromaleic acid salt, difluoro maleic acid salt, or combinationsthereof.

In some embodiments, the sulfonic acid group-containing monomer isvinylsulfonic acid, methylvinylsulfonic acid, allylvinylsulfonic acid,allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid,2-sulfoethyl methacrylic acid, 2-methylprop-2-ene-1-sulfonic acid,2-acrylamido-2-methyl-1-propane sulfonic acid,3-allyloxy-2-hydroxy-1-propane sulfonic acid, allyl hydrogensulfate,vinyl hydrogensulfate, or combinations thereof.

In some embodiments, the sulfonic acid salt group-containing monomer isvinylsulfonic acid salt, methylvinylsulfonic acid salt,allylvinylsulfonic acid salt, allylsulfonic acid salt, methallylsulfonicacid salt, styrenesulfonic acid salt, 2-sulfoethyl methacrylic acidsalt, 2-methylprop-2-ene-1-sulfonic acid salt,2-acrylamido-2-methyl-1-propane sulfonic acid salt,3-allyloxy-2-hydroxy-1-propane sulfonic acid salt, allyl sulfate salt,vinyl sulfate salt, or combinations thereof.

In some embodiments, the phosphonic acid group-containing monomer isvinyl phosphonic acid, allyl phosphonic acid, vinyl benzyl phosphonicacid, acrylamide alkyl phosphonic acid, methacrylamide alkyl phosphonicacid, acrylamide alkyl diphosphonic acid, acryloylphosphonic acid,2-methacryloyloxyethyl phosphonic acid, bis(2-methacryloyloxyethyl)phosphonic acid, ethylene 2-methacryloyloxyethyl phosphonic acid,ethyl-methacryloyloxyethyl phosphonic acid, allyl hydrogenphosphate,vinyl hydrogenphosphate, or combinations thereof.

In some embodiments, the phosphonic acid salt group-containing monomeris salt of vinyl phosphonic acid, salt of allyl phosphonic acid, salt ofvinyl benzyl phosphonic acid, salt of acrylamide alkyl phosphonic acid,salt of methacrylamide alkyl phosphonic acid, salt of acrylamide alkyldiphosphonic acid, salt of acryloylphosphonic acid, salt of2-methacryloyloxyethyl phosphonic acid, salt ofbis(2-methacryloyloxyethyl) phosphonic acid, salt of ethylene2-methacryloyloxyethyl phosphonic acid, salt ofethyl-methacryloyloxyethyl phosphonic acid, allyl phosphate salt, vinylphosphate salt, or combinations thereof.

In some embodiments, the proportion of structural unit (a) within thecopolymer is from about 15% to about 30%, from about 16% to about 30%,from about 17% to about 30%, from about 18% to about 30%, from about 19%to about 30%, from about 20% to about 30%, from about 21% to about 30%,from about 22% to about 30%, from about 23% to about 30%, from about 24%to about 30%, from about 25% to about 30%, from about 15% to about 27%,from about 16% to about 27%, from about 17% to about 27%, from about 18%to about 27%, from about 19% to about 27%, from about 20% to about 27%,from about 21% to about 27%, from about 22% to about 27%, from about 15%to about 25%, from about 16% to about 25%, from about 17% to about 25%,from about 18% to about 25%, from about 19% to about 25%, or from about20% to about 25% by mole, based on the total number of moles ofmonomeric units in the copolymeric binder.

In some embodiments, the proportion of structural unit (a) within thecopolymer is less than 30%, less than 29%, less than 28%, less than 27%,less than 26%, less than 25%, less than 24%, less than 23%, less than22%, less than 21%, or less than 20% by mole, based on the total numberof moles of monomeric units in the copolymeric binder. In someembodiments, the proportion of structural unit (a) within the copolymeris more than 15%, more than 16%, more than 17%, more than 18%, more than19%, more than 20%, more than 21%, more than 22%, more than 23%, morethan 24%, or more than 25% by mole, based on the total number of molesof monomeric units in the copolymeric binder.

In some embodiments, the copolymer additionally comprises a structuralunit (b), derived from a monomer selected from the group consisting ofan amide group-containing monomer, a hydroxyl group-containing monomer,and combinations thereof.

In some embodiments, the amide group-containing monomer is acrylamide,methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide,N-n-propyl methacrylamide, N-isopropyl methacrylamide, isopropylacrylamide, N-n-butyl methacrylamide, N-isobutyl methacrylamide,N,N-dimethyl acrylamide, N,N-dimethyl methacrylamide, N,N-diethylacrylamide, N,N-diethyl methacrylamide, N-methylol methacrylamide,N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide,N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide,N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylol methacrylamide, diacetone methacrylamide,diacetone acrylamide, methacryloyl morpholine, N-hydroxylmethacrylamide, N-methoxymethyl acrylamide, N-methoxymethylmethacrylamide, N,N′-methylene-bis-acrylamide (MBA), N-hydroxymethylacrylamide, or combinations thereof.

In some embodiments, the hydroxyl group-containing monomer is a C₁ toC₂₀ alkyl group or a C₅ to C₂₀ cycloalkyl group-containing methacrylatehaving a hydroxyl group. In some embodiments, the hydroxylgroup-containing monomer is 2-hydroxyethylacrylate, 2-hydroxyethylmethacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,2-hydroxybutyl methacrylate, 3-hydroxypropylacrylate,3-hydroxypropylmethacrylate, 4-hydroxybutyl methacrylate,5-hydroxypentylacrylate, 6-hydroxyhexyl methacrylate,1,4-cyclohexanedimethanol mono(meth)acrylate, 3-chloro-2-hydroxypropylmethacrylate, diethylene glycol mono(meth)acrylate, allyl alcohol, orcombinations thereof.

In some embodiments, the proportion of structural unit (b) within thecopolymer is from about 5% to about 20%, from about 6% to about 20%,from about 7% to about 20%, from about 8% to about 20%, from about 9% toabout 20%, from about 10% to about 20%, from about 11% to about 20%,from about 12% to about 20%, from about 13% to about 20%, from about 14%to about 20%, from about 15% to about 20%, from about 5% to about 17%,from about 6% to about 17%, from about 7% to about 17%, from about 8% toabout 17%, from about 9% to about 17%, from about 10% to about 17%, fromabout 11% to about 17%, from about 12% to about 17%, from about 5% toabout 15%, from about 6% to about 15%, from about 7% to about 15%, fromabout 8% to about 15%, from about 9% to about 15%, or from about 10% toabout 15% by mole, based on the total number of moles of monomeric unitsin the copolymeric binder.

In some embodiments, the proportion of structural unit (b) within thecopolymer is less than 20%, less than 19%, less than 18%, less than 17%,less than 16%, less than 15%, less than 14%, less than 13%, less than12%, less than 11%, or less than 10% by mole, based on the total numberof moles of monomeric units in the copolymeric binder. In someembodiments, the proportion of structural unit (b) within the copolymeris more than 5%, more than 6%, more than 7%, more than 8%, more than 9%,more than 10%, more than 11%, more than 12%, more than 13%, more than14%, or more than 15% by mole, based on the total number of moles ofmonomeric units in the copolymeric binder.

In some embodiments, the copolymer additionally comprises a structuralunit (c), derived from a monomer selected from the group consisting of anitrile group-containing monomer, ester group-containing monomer, epoxygroup-containing monomer, a fluorine-containing monomer, andcombinations thereof.

In some embodiments, the nitrile group-containing monomer includesα,β-ethylenically unsaturated nitrile monomers. In some embodiments, thenitrile group-containing monomer is acrylonitrile,α-halogenoacrylonitrile, α-alkylacrylonitrile, or combinations thereof.In some embodiments, the nitrile group-containing monomer isα-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile,methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile,α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile,3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile,α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile,α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidenecyanide, or combinations thereof.

In some embodiments, the ester group-containing monomer is C₁ to C₂₀alkyl acrylate, C₁ to C₂₀ alkyl (meth)acrylate, cycloalkyl acrylate, orcombinations thereof. In some embodiments, the ester group-containingmonomer is methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropylacrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate,pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate,3,3,5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate,decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, oxtadecylacrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate,methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate,perfluorooctyl acrylate, stearyl acrylate, or combinations thereof. Insome embodiments, the ester group-containing monomer is cyclohexylacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornylmethacrylate, 3,3,5-trimethylcyclohexylacrylate, or combinationsthereof. In some embodiments, the ester group-containing monomer ismethyl methacrylate, ethyl methacrylate, n-propyl methacrylate,isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate,tert-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate,isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octylmethacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decylmethacrylate, lauryl methacrylate, n-tetradecyl methacrylate, stearylmethacrylate, 2,2,2-trifluoroethyl methacrylate, phenyl methacrylate,benzyl methacrylate, or combinations thereof.

In some embodiments, the epoxy group-containing monomer is vinylglycidyl ether, allyl glycidyl ether, allyl 2,3-epoxypropyl ether,butenyl glycidyl ether, butadiene monoepoxide, chloroprene monoepoxide,3,4-epoxy-1-butene, 4,5-epoxy-2-pentene, 3,4-epoxy-1-vinylcyclohexane,1,2-epoxy-4-vinylcyclohexane, 3,4-epoxy cyclohexylethylene,epoxy-4-vinylcyclohexene, 1,2-epoxy-5,9-cyclododecadiene, orcombinations thereof.

In some embodiments, the epoxy group-containing monomer is3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, 1,2-epoxy-9-decene, glycidylacrylate, glycidyl methacrylate, glycidyl crotonate, glycidyl2,4-dimethyl pentenoate, glycidyl 4-hexenoate, glycidyl 4-heptenoate,glycidyl 5-methyl-4-heptenoate, glycidyl sorbate, glycidyl linoleate,glycidyl oleate, glycidyl 3-butenoate, glycidyl 3-pentenoate,glycidyl-4-methyl-3-pentenoate, or combinations thereof.

In some embodiments, the fluorine-containing monomer is a C₁ to C₂₀alkyl group-containing acrylate, methacrylate, or combinations thereof,wherein the monomer comprises at least one fluorine atom. In someembodiments, the fluorine-containing monomer is perfluoro alkyl acrylatesuch as perfluoro dodecyl acrylate, perfluoro n-octyl acrylate,perfluoro n-butyl acrylate, perfluoro hexylethyl acrylate and perfluorooctylethyl acrylate; perfluoro alkyl methacrylate such as perfluorododecyl methacrylate, perfluoro n-octyl methacrylate, perfluoro n-butylmethacrylate, perfluoro hexylethyl methacrylate and perfluoro octylethylmethacrylate; perfluoro oxyalkyl acrylate such as perfluorododecyloxyethyl acrylate and perfluoro decyloxyethyl acrylate; perfluorooxyalkyl methacrylate such as perfluoro dodecyloxyethyl methacrylate andperfluoro decyloxyethyl methacrylate, or combinations thereof. In someembodiments, the fluorine-containing monomer is a carboxylate containingat least one C₁ to C₂₀ alkyl group and at least one fluorine atom;wherein the carboxylate is selected from the group consisting ofcrotonate, malate, fumarate, itaconate, or combinations thereof. In someembodiments, the fluorine-containing monomer is vinyl fluoride,trifluoroethylene, trifluorochloroethylene, fluoroalkyl vinyl ether,perfluoroalkyl vinyl ether, hexafluoropropylene,2,3,3,3-tetrafluoropropene, vinylidene fluoride, tetrafluoroethylene,2-fluoro acrylate, or combinations thereof.

In some embodiments, the proportion of structural unit (c) within thecopolymer is from about 50% to about 75%, from about 51% to about 75%,from about 52% to about 75%, from about 53% to about 75%, from about 54%to about 75%, from about 55% to about 75%, from about 56% to about 75%,from about 57% to about 75%, from about 58% to about 75%, from about 59%to about 75%, from about 60% to about 75%, from about 61% to about 75%,from about 62% to about 75%, from about 63% to about 75%, from about 64%to about 75%, from about 65% to about 75%, from about 50% to about 70%,from about 51% to about 70%, from about 52% to about 70%, from about 53%to about 70%, from about 54% to about 70%, from about 55% to about 70%,from about 56% to about 70%, from about 57% to about 70%, from about 58%to about 70%, from about 59% to about 70%, from about 60% to about 70%,from about 61% to about 70%, from about 62% to about 70%, from about 63%to about 70%, from about 64% to about 70%, from about 65% to about 70%,from about 55% to about 65%, from about 56% to about 65%, from about 57%to about 65%, from about 58% to about 65%, from about 59% to about 65%,or from about 60% to about 65% by mole, based on the total number ofmoles of monomeric units in the copolymeric binder.

In some embodiments, the proportion of structural unit (c) within thecopolymer is less than 75%, less than 74%, less than 73%, less than 72%,less than 71%, less than 70%, less than 69%, less than 68%, less than67%, less than 66%, less than 65%, less than 64%, less than 63%, lessthan 62%, less than 61%, less than 60%, less than 59%, less than 58%,less than 57%, less than 56%, or less than 55% by mole, based on thetotal number of moles of monomeric units in the copolymeric binder. Insome embodiments, the proportion of structural unit (c) within thecopolymer is more than 50%, more than 51%, more than 52%, more than 53%,more than 54%, more than 55%, more than 56%, more than 57%, more than58%, more than 59%, more than 60%, more than 61%, more than 62%, morethan 63%, more than 64%, more than 65%, more than 66%, more than 67%,more than 68%, more than 69%, or more than 70% by mole, based on thetotal number of moles of monomeric units in the copolymeric binder.

In other embodiments, the copolymer may additionally comprise astructural unit derived from an olefin. Any hydrocarbon that has atleast one carbon-carbon double bond may be used as an olefin without anyspecific limitations. In some embodiments, the olefin includes a C₂ toC₂₀ aliphatic compound, a C₈ to C₂₀ aromatic compound or a cycliccompound containing vinylic unsaturation, a C₄ to C₄₀ diene, andcombinations thereof. In some embodiments, the olefin is styrene,ethylene, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene,1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, cyclobutene,3-methyl-1-pentene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene,4-vinylcyclohexene, vinyl cyclohexane, norbornene, norbornadiene,ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene,cyclooctene, or combinations thereof. In some embodiments, the copolymerdoes not comprise a structural unit derived from an olefin. In someembodiments, the copolymer does not comprise a structural unit derivedfrom styrene, ethylene, propylene, isobutylene, 1-butene, 1-pentene,1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene,3-methyl-1-butene, cyclobutene, 3-methyl-l-pentene, 4-methyl-l-pentene,4,6-dimethyl- 1-heptene, 4-vinylcyclohexene, vinyl cyclohexane,norbornene, norbornadiene, ethylidene norbornene, cyclopentene,cyclohexene, dicyclopentadiene or cyclooctene.

A conjugated diene group-containing monomer constitutes as an olefin. Insome embodiments, a conjugated diene group-containing monomer includesC₄ to C₄₀ dienes; aliphatic conjugated diene monomers such as1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene, 1,5-hexadiene,1,7-octadiene, 1,9-decadiene, isoprene, myrcene, 2-methyl-1,3-butadiene,2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene; substituted linearconjugated pentadienes, substituted side chain conjugated hexadienes;and combinations thereof. In some embodiments, the copolymer does notcomprise a structural unit derived from C₄ to C₄₀ dienes; aliphaticconjugated diene monomers such as 1,3-butadiene, 1,3-pentadiene,1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, isoprene,myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene,2-chloro-1,3-butadiene; substituted linear conjugated pentadienes; orsubstituted side chain conjugated hexadienes.

In other embodiments, the copolymer may additionally comprise astructural unit derived from an aromatic vinyl group-containing monomer.In some embodiments, the aromatic vinyl group-containing monomer isstyrene, α-methylstyrene, vinyltoluene, divinylbenzene, or combinationsthereof. In some embodiments, the copolymer does not comprise astructural unit derived from an aromatic vinyl group-containing monomer.In some embodiments, the copolymer does not comprise a structural unitderived from styrene, a-methylstyrene, vinyltoluene or divinylbenzene.

In some embodiments, the metal substrate can be in the form of a foil,sheet or film. In some embodiments, the metal substrate is selected fromthe group consisting of stainless steel, titanium, nickel, aluminum,copper, platinum, gold, silver, chromium, zirconium, tungsten,molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and alloysthereof. In some embodiments, the metal substrate can comprise two ormore layers, wherein the material of each layer is selected from thegroup consisting of stainless steel, titanium, nickel, aluminum, copper,platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin,vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof. In someembodiments, the metal substrate has a two-layered structure. In someembodiments, the metal substrate has three or more layers. In someembodiments, the metal substrate only has one layer. In someembodiments, the materials of each layer in the metal substrate are thesame. In some embodiments, the materials of each layer in the metalsubstrate are different, or partially different.

In some embodiments, when the metal substrate comprises more than onelayer, the metal substrate comprises a layer of insulating material. Insome embodiments, the insulating material is a polymeric materialselected from the group consisting of polycarbonate, polyacrylate,polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane,polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyolefin,polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester),polyvinyl chloride, polyether, polyphenylene oxide, cellulose polymer,and combinations thereof. When the metal substrate comprises a layer ofinsulating material, the coating is coated onto the metal layer(s) onthe outside of the substrate.

In some embodiments, the metal substrate is coated with a layer ofcarbonaceous material. Such a layer of carbonaceous material would bepart of the coating layer. In some embodiments, the metal substrate isnot coated with a layer of carbonaceous material.

When the composite is immersed into the delamination solution for aninadequate amount of time, the delamination agent and the aqueoussolvent contained in the delamination solution might not possesssufficient time to destabilize, disrupt and break the bonds that areinitially formed between the coating and the metal substrate surface toan extent that complete delamination of the composite is made possible.However, when the composite is immersed into the delamination solutionfor a prolonged period of time, corrosion of the metal substrate mightoccur due to extended contact time of the composite with thedelamination agent (e.g. strong base) contained within the delaminationsolution. There is no particular limitation on the time taken fordelamination, but the time taken should be sufficiently long as to allowfor full delamination to occur, but sufficiently short as to ensurecorrosion of the metal substrate does not occur.

In some embodiments, the composite is immersed into the delaminationsolution for a time period of from about 1 second to about 120 minutes,from about 5 seconds to about 120 minutes, from about 10 seconds toabout 120 minutes, from about 20 seconds to about 120 minutes, fromabout 30 seconds to about 120 minutes, from about 45 seconds to about120 minutes, from about 60 seconds to about 120 minutes, from about 75seconds to about 120 minutes, from about 90 seconds to about 120minutes, from about 105 seconds to about 120 minutes, from about 120seconds to about 120 minutes, from 30 seconds to about 90 minutes, from30 seconds to about 75 minutes, from 30 seconds to about 60 minutes,from 30 seconds to about 45 minutes, from 30 seconds to about 30minutes, from 30 seconds to about 20 minutes, from 30 seconds to about10 minutes, from 30 seconds to about 5 minutes, from 60 seconds to about90 minutes, from 60 seconds to about 75 minutes, from 60 seconds toabout 60 minutes, from 60 seconds to about 45 minutes, from 60 secondsto about 30 minutes, from 60 seconds to about 20 minutes, from 60seconds to about 10 minutes, from 60 seconds to about 5 minutes, fromabout 120 seconds to about 60 minutes, from about 120 seconds to about45 minutes, from about 120 seconds to about 30 minutes, from about 120seconds to about 20 minutes, from about 120 seconds to about 10 minutes,or from about 120 seconds to about 5 minutes.

In some embodiments, the composite is immersed into the delaminationsolution for a time period of less than 120 minutes, less than 105minutes, less than 90 minutes, less than 75 minutes, less than 60minutes, less than 45 minutes, less than 30 minutes, less than 20minutes, less than 10 minutes, less than 5 minutes, less than 1 minute,less than 45 seconds, less than 30 seconds, less than 20 seconds, orless than 10 seconds. In some embodiments, the composite is immersedinto the delamination solution for a time period of more than 1 second,more than 5 seconds, more than 10 seconds, more than 20 seconds, morethan 30 seconds, more than 45 seconds, more than 60 seconds, more than75 seconds, more than 90 seconds, more than 105 seconds, more than 120seconds, more than 5 minutes, more than 10 minutes, more than 20minutes, or more than 30 minutes.

There is no particular limitation on the temperature of delamination,but the temperature should not be too low as to require an extremelylong time to achieve full delamination, nor should the temperature betoo high as to pose a health and safety risk.

In some embodiments, the composite is immersed into the delaminationsolution at a temperature of from about 10° C. to about 90° C., fromabout 15° C. to about 90° C., from about 20° C. to about 90° C., fromabout 25° C. to about 90° C., from about 30° C. to about 90° C., fromabout 35° C. to about 90° C., from about 40° C. to about 90° C., fromabout 45° C. to about 90° C., from about 50° C. to about 90° C., fromabout 55° C. to about 90° C., from about 60° C. to about 90° C., fromabout 65° C. to about 90° C., from about 70° C. to about 90° C., fromabout 75° C. to about 90° C., from about 20° C. to about 75° C., fromabout 25° C. to about 75° C., from about 30° C. to about 75° C., fromabout 35° C. to about 75° C., from about 40° C. to about 75° C., fromabout 45° C. to about 75° C., from about 50° C. to about 75° C., fromabout 55° C. to about 75° C., from about 60° C. to about 75° C., fromabout 25° C. to about 60° C., from about 30° C. to about 60° C., fromabout 35° C. to about 60° C., from about 40° C. to about 60° C., or fromabout 45° C. to about 60° C.

In some embodiments, the composite is immersed into the delaminationsolution at a temperature of less than 90° C., less than 85° C., lessthan 80° C., less than 75° C., less than 70° C., less than 65° C., lessthan 60° C., less than 55° C., less than 50° C., less than 45° C., lessthan 40° C., less than 35° C., or less than 30° C. In some embodiments,the composite is immersed into the delamination solution at atemperature of more than 10° C., more than 15° C., more than 20° C.,more than 25° C., more than 30° C., more than 35° C., more than 40° C.,more than 45° C., more than 50° C., more than 55° C., more than 60° C.,more than 65° C., or more than 70° C.

When there is an insufficient amount of delamination solution used forimmersion of a given amount of composite, full delamination of thecomposite cannot take place. An example of the consequence of such is alarge proportion of the coating might still be found deposited oradhered on the surface of the metal substrate. There is no particulardisadvantage to using too much delamination solution with respect todelamination performance, although this would represent a waste of rawmaterials, and in addition may produce unnecessary contaminated orpolluted aqueous solvent waste that requires further treatment steps forsolvent reuse. Accordingly, there is no particular limitation on theratio of composite to delamination solution, except that the ratio ofdelamination solution to composite should be sufficient to enable thedelamination of all the composite present, and furthermore it is notrecommended that an overly large ratio of delamination agent tocomposite is used for cost reasons.

In some embodiments, as the composite is immersed into the delaminationsolution to achieve delamination of the composite, the weight ratio ofthe composite to the delamination solution is from about 0.01% to about50%, from about 0.02% to about 50%, from about 0.05% to about 50%, fromabout 0.1% to about 50%, from about 0.2% to about 50%, from about 0.5%to about 50%, from about 1% to about 50%, from about 2% to about 50%,from about 5% to about 50%, from about 10% to about 50%, from about 15%to about 50%, from about 20% to about 50%, from about 25% to about 50%,from about 30% to about 50%, from about 0.01% to about 25%, from about0.02% to about 25%, from about 0.05% to about 25%, from about 0.1% toabout 25%, from about 0.2% to about 25%, from about 0.5% to about 25%,from about 1% to about 25%, from about 2% to about 25%, from about 5% toabout 25%, from about 10% to about 25%, from about 0.1% to about 15%,from about 0.2% to about 15%, from about 0.5% to about 15%, from about1% to about 15%, from about 2% to about 15%, from about 5% to about 15%,from about 0.1% to about 5%, from about 0.2% to about 5%, from about0.5% to about 5%, from about 1% to about 5%, or from about 2% to about5%.

In some embodiments, as the composite is immersed into the delaminationsolution to achieve delamination of the composite, the weight ratio ofthe composite to the delamination solution is less than 50%, less than45%, less than 40%, less than 35%, less than 30%, less than 25%, lessthan 20%, less than 15%, less than 10%, less than 5%, less than 2%, lessthan 1%, less than 0.5%, less than 0.2%, less than 0.1%, or less than0.05%. In some embodiments, as the composite is immersed into thedelamination solution to achieve delamination of the composite, theweight ratio of the composite to the delamination solution is more than0.01%, more than 0.02%, more than 0.05%, more than 0.1%, more than 0.2%,more than 0.5%, more than 1%, more than 2%, more than 5%, more than 10%,more than 15%, more than 20%, more than 25%, more than 30%, more than35%, or more than 40%.

The purpose of the delamination agent is to interrupt and break theion-dipole interactions and hydrogen bonding interactions between thecopolymeric binder contained in the coating and the metal substratesurface. A sufficient concentration of delamination agent in thedelamination solution is required to efficiently disrupt interactionsbetween the coating and the metal substrate and thus cause delaminationof the composite. Relatively low concentrations of the delaminationagent are adequate to induce disruption of the interactions between thecopolymeric binder within the coating, and the metal substrate surface.The use of delamination agent of low concentrations for immersion of thecomposite reduces the likelihood of corrosion of the metal substrate andother possible metal components of the composite and/or mitigates sidereaction(s) that might arise from the use of high-concentrationdelamination agent.

In some embodiments, the concentration of the delamination agent in thedelamination solution is from about 0.3 M to about 3 M, from about 0.5 Mto about 3 M, from about 0.75 M to about 3 M, from about 1 M to about 3M, from about 1.25 M to about 3 M, from about 1.5 M to about 3 M, fromabout 1.75 M to about 3 M, from about 2 M to about 3 M, from about 2.25M to about 3 M, from about 2.5 M to about 3 M, from about 0.3 M to about2.5 M, from about 0.5 M to about 2.5 M, from about 0.75 M to about 2.5M, from about 1 M to about 2.5 M, from about 1.25 M to about 2.5 M, fromabout 1.5 M to about 2.5 M, from about 1.75 M to about 2.5 M, from about0.3 M to about 2 M, from about 0.5 M to about 2 M, from about 0.75 M toabout 2 M, from about 1 M to about 2 M, from about 1.25 M to about 2 M,from about 0.3 M to about 1.5 M, from about 0.5 M to about 1.5 M, fromabout 0.75 M to about 1.5 M, or from about 1 M to about 1.5 M.

In some embodiments, the concentration of the delamination agent in thedelamination solution is less than 3 M, less than 2.75 M, less than 2.5M, less than 2.25 M, less than 2 M, less than 1.75 M, less than 1.5 M,less than 1.25 M, less than 1 M, or less than 0.75 M. In someembodiments, the concentration of the delamination agent in thedelamination solution is more than 0.3 M, more than 0.5 M, more than0.75 M, more than 1 M, more than 1.25 M, more than 1.5 M, more than 1.75M, more than 2 M, more than 2.25 M, or more than 2.5 M.

In some embodiments, the surface density of the coating is from about 1mg/cm² to about 50 mg/cm², from about 2.5 mg/cm² to about 50 mg/cm²,from about 5 mg/cm² to about 50 mg/cm², from about 7.5 mg/cm² to about50 mg/cm², from about 10 mg/cm² to about 50 mg/cm², from about 12.5mg/cm² to about 50 mg/cm², from about 15 mg/cm² to about 50 mg/cm², fromabout 17.5 mg/cm² to about 50 mg/cm², from about 20 mg/cm² to about 50mg/cm², from about 25 mg/cm² to about 50 mg/cm², from about 30 mg/cm² toabout 50 mg/cm², from about 1 mg/cm² to about 30 mg/cm², from about 2.5mg/cm² to about 30 mg/cm², from about 5 mg/cm² to about 30 mg/cm², fromabout 7.5 mg/cm² to about 30 mg/cm², from about 10 mg/cm² to about 30mg/cm², from about 12.5 mg/cm² to about 30 mg/cm², from about 15 mg/cm²to about 30 mg/cm², from about 17.5 mg/cm² to about 30 mg/cm², fromabout 20 mg/cm² to about 30 mg/cm², from about 1 mg/cm² to about 20mg/cm², from about 2.5 mg/cm² to about 20 mg/cm², from about 5 mg/cm² toabout 20 mg/cm², from about 7.5 mg/cm² to about 20 mg/cm², from about 10mg/cm² to about 20 mg/cm², from about 12.5 mg/cm² to about 20 mg/cm²,from about 1 mg/cm² to about 15 mg/cm², from about 2.5 mg/cm² to about15 mg/cm², from about 5 mg/cm² to about 15 mg/cm², from about 7.5 mg/cm²to about 15 mg/cm², or from about 10 mg/cm² to about 15 mg/cm².

In some embodiments, the surface density of the coating is less than 50mg/cm², less than 45 mg/cm², less than 35 mg/cm², less than 30 mg/cm²,less than 25 mg/cm², less than 20 mg/cm², less than 17.5 mg/cm², lessthan 15 mg/cm², less than 12.5 mg/cm², less than 10 mg/cm², less than7.5 mg/cm², less than 5 mg/cm², or less than 2.5 mg/cm2. In someembodiments, the surface density of the coating is more than 1 mg/cm²,more than 2.5 mg/cm², more than 5 mg/cm², more than 7.5 mg/cm², morethan 10 mg/cm², more than 12.5 mg/cm², more than 15 mg/cm², more than17.5 mg/cm², more than 20 mg/cm², more than 25 mg/cm², more than 30mg/cm², more than 35 mg/cm², or more than 40 mg/cm².

In some embodiments, the density of the coating is from about 0.5 g/cm³to about 7.5 g/cm³, from about 1 g/cm³ to about 7.5 g/cm³, from about1.5 g/cm³ to about 7.5 g/cm³, from about 2 g/cm³ to about 7.5 g/cm³,from about 2.5 g/cm³ to about 7.5 g/cm³, from about 3 g/cm³ to about 7.5g/cm³, from about 3.5 g/cm³ to about 7.5 g/cm³, from about 4 g/cm³ toabout 7.5 g/cm³, from about 4.5 g/cm3 to about 7.5 g/cm³, from about 5g/cm³ to about 7.5 g/cm³, from about 0.5 g/cm³ to about 5 g/cm³, fromabout 1 g/cm³ to about 5 g/cm³, from about 1.5 g/cm³ to about 5 g/cm³,from about 2 g/cm³ to about 5 g/cm³, from about 2.5 g/cm³ to about 5g/cm³, from about 3 g/cm³ to about 5 g/cm3, from about 0.5 g/cm3 toabout 2.5 g/cm3, from about 1 g/cm³ to about 2.5 g/cm³, or from about1.5 g/cm³ to about 2.5 g/cm³.

In some embodiments, the density of the coating is less than 7.5 g/cm³,less than 7 g/cm³, less than 6.5 g/cm³, less than 6 g/cm³, less than 5.5g/cm³, less than 5 g/cm³, less than 4.5 g/cm³, less than 4 g/cm³, lessthan 3.5 g/cm³, less than 3 g/cm³, less than 2.5 g/cm³, less than 2g/cm³, or less than 1.5 g/cm³. In some embodiments, the density of thecoating is more than 0.5 g/cm³, more than 1 g/cm³, more than 1.5 g/cm3,more than 2 g/cm³, more than 2.5 g/cm3, more than 3 g/cm³, more than 3.5g/cm³, more than 4 g/cm³, more than 4.5 g/cm3, more than 5 g/cm3, morethan 5.5 g/cm³, more than 6 g/cm³, or more than 6.5 g/cm³.

In some embodiments, the composite-delamination solution mixture isstirred while the composite is immersed into the delamination solutionto achieve delamination of the composite. In some embodiments, aplanetary stirring mixer, a stirring mixer, a blender, anultrasonicator, or combinations thereof is used to stir thecomposite-delamination solution mixture. In other embodiments, thecomposite-delamination solution mixture is not stirred while thecomposite is immersed in the delamination solution.

In some embodiments, the composite-delamination solution mixture isstirred at a speed of from about 10 rpm to about 3000 rpm, from about 20rpm to about 3000 rpm, from about 50 rpm to about 3000 rpm, from about100 rpm to about 3000 rpm, from about 200 rpm to about 3000 rpm, fromabout 250 rpm to about 3000 rpm, from about 300 rpm to about 3000 rpm,from about 400 rpm to about 3000 rpm, from about 500 rpm to about 3000rpm, from about 600 rpm to about 3000 rpm, from about 750 rpm to about3000 rpm, from about 900 rpm to about 3000 rpm, from about 1200 rpm toabout 3000 rpm, from about 1500 rpm to about 3000 rpm, from about 10 rpmto about 1000 rpm, from about 20 rpm to about 1000 rpm, from about 50rpm to about 1000 rpm, from about 100 rpm to about 1000 rpm, from about200 rpm to about 1000 rpm, from about 250 rpm to about 1000 rpm, fromabout 300 rpm to about 1000 rpm, from about 400 rpm to about 1000 rpm,from about 500 rpm to about 1000 rpm, from about 10 rpm to about 750rpm, from about 20 rpm to about 750 rpm, from about 50 rpm to about 750rpm, from about 100 rpm to about 750 rpm, from about 200 rpm to about750 rpm, from about 250 rpm to about 750 rpm, from about 300 rpm toabout 750 rpm, from about 10 rpm to about 500 rpm, from about 20 rpm toabout 500 rpm, from about 50 rpm to about 500 rpm, from about 100 rpm toabout 500 rpm, or from about 200 rpm to about 500 rpm.

In some embodiments, the composite-delamination solution mixture isstirred at a speed of less than 3000 rpm, less than 2500 rpm, less than1500 rpm, less than 1200 rpm, less than 900 rpm, less than 750 rpm, lessthan 600 rpm, less than 500 rpm, less than 400 rpm, less than 300 rpm,or less than 250 rpm. In some embodiments, the composite-delaminationsolution mixture is stirred at a speed of more than 10 rpm, more than 20rpm, more than 50 rpm, more than 100 rpm, more than 200 rpm, more than250 rpm, more than 300 rpm, more than 400 rpm, more than 500 rpm, morethan 600 rpm, or more than 750 rpm.

In some embodiments, the composite-delamination solution mixture isstirred for a time period of from about 1 second to about 120 minutes,from about 5 seconds to about 120 minutes, from about 10 seconds toabout 120 minutes, from about 20 seconds to about 120 minutes, fromabout 30 seconds to about 120 minutes, from about 45 seconds to about120 minutes, from about 60 seconds to about 120 minutes, from about 75seconds to about 120 minutes, from about 90 seconds to about 120minutes, from about 105 seconds to about 120 minutes, from about 120seconds to about 120 minutes, from 30 seconds to about 90 minutes, from30 seconds to about 75 minutes, from 30 seconds to about 60 minutes,from 30 seconds to about 45 minutes, from 30 seconds to about 30minutes, from 30 seconds to about 20 minutes, from 30 seconds to about10 minutes, from 30 seconds to about 5 minutes, from 60 seconds to about90 minutes, from 60 seconds to about 75 minutes, from 60 seconds toabout 60 minutes, from 60 seconds to about 45 minutes, from 60 secondsto about 30 minutes, from 60 seconds to about 20 minutes, from 60seconds to about 10 minutes, from 60 seconds to about 5 minutes, fromabout 120 seconds to about 60 minutes, from about 120 seconds to about45 minutes, from about 120 seconds to about 30 minutes, from about 120seconds to about 20 minutes, from about 120 seconds to about 10 minutes,or from about 120 seconds to about 5 minutes.

In some embodiments, the composite-delamination solution mixture isstirred for a time period of less than 120 minutes, less than 105minutes, less than 90 minutes, less than 75 minutes, less than 60minutes, less than 45 minutes, less than 30 minutes, less than 20minutes, less than 10 minutes, less than 5 minutes, less than 1 minute,less than 45 seconds, less than 30 seconds, less than 20 seconds, orless than 10 seconds. In some embodiments, the composite-delaminationsolution mixture is stirred for a time period of more than 1 second,more than 5 seconds, more than 10 seconds, more than 20 seconds, morethan 30 seconds, more than 45 seconds, more than 60 seconds, more than75 seconds, more than 90 seconds, more than 105 seconds, more than 120seconds, more than 5 minutes, more than 10 minutes, more than 20minutes, or more than 30 minutes.

In some embodiments, the planetary stirring mixer comprises at least oneplanetary blade and at least one high-speed dispersion blade. In certainembodiments, the rotational speed of the planetary blade is from about20 rpm to about 200 rpm, from about 20 rpm to about 150 rpm, from about30 rpm to about 150 rpm, or from about 50 rpm to about 100 rpm. Incertain embodiments, the rotational speed of the dispersion blade isfrom about 1,000 rpm to about 4,000 rpm, from about 1,000 rpm to about3,500 rpm, from about 1,000 rpm to about 3,000 rpm, from about 1,000 rpmto about 2,000 rpm, from about 1,500 rpm to about 3,000 rpm, or fromabout 1,500 rpm to about 2,500 rpm.

In certain embodiments, the ultrasonicator is an ultrasonic bath, aprobe-type ultrasonicator or an ultrasonic flow cell. In someembodiments, the ultrasonicator is operated at a power density fromabout 10 W/L to about 100 W/L, from about 20 W/L to about 100 W/L, fromabout 30 W/L to about 100 W/L, from about 40 W/L to about 80 W/L, fromabout 40 W/L to about 70 W/L, from about 40 W/L to about 60 W/L, fromabout 40 W/L to about 50 W/L, from about 50 W/L to about 60 W/L, fromabout 20 W/L to about 80 W/L, from about 20 W/L to about 60 W/L, or fromabout 20 W/L to about 40 W/L. In certain embodiments, the ultrasonicatoris operated at a power density of more than 10 W/L, more than 20 W/L,more than 30 W/L, more than 40 W/L, more than 50 W/L, more than 60 W/L,more than 70 W/L, more than 80 W/L or more than 90 W/L.

In some embodiments, the ultrasonicator operates at a power from about100 W to about 1000 W, from about 200 W to about 1000 W, from about 300W to about 1000 W, from about 400 W to about 1000 W, from about 500 W toabout 1000 W, from about 500 W to about 900 W, from about 500 W to about800 W, from about 500 W to about 700 W, or from about 500 W to about 600W. In some embodiments, the ultrasonicator operates at a power of lessthan 1000 W, less than 900 W, less than 800 W, less than 700 W, lessthan 600 W, less than 500 W, less than 400 W, or less than 300 W. Insome embodiments, the ultrasonicator operates at a power of more than100 W, more than 200 W, more than 300 W, more than 400 W, more than 500W, more than 600 W, more than 700 W, or more than 800 W.

In some embodiments, after the immersion of the composite into thedelamination solution, the pH of the composite-delamination solutionmixture following delamination is from about 10 to about 14, from about10.25 to about 14, from about 10.5 to about 14, from about 10.75 toabout 14, from about 11 to about 14, from about 11.25 to about 14, fromabout 11.5 to about 14, from about 11.5 to about 13.75, from about 11.5to about 13.5, from about 11.5 to about 13.25, from about 11.5 to about13, from about 11.5 to about 12.75, or from about 11.5 to about 12.5.

In some embodiments, after the immersion of the composite into thedelamination solution, the pH of the composite-delamination solutionmixture following delamination is less than 14, less than 13.75, lessthan 13.5, less than 13.25, less than 13, less than 12.75, less than12.5, less than 12.25, less than 12, less than 11.75, or less than 11.5.In some embodiments, after the immersion of the composite into thedelamination solution, the pH of the composite-delamination solutionmixture following delamination is more than 10, more than 10.25, morethan 10.5, more than 10.75, more than 11, more than 11.25, more than11.5, more than 11.75, more than 12, more than 12.25, or more than 12.5.

In some embodiments, after the immersion of the composite into thedelamination solution, the composite is delaminated into two or morelayers. In some embodiments, after the immersion of the composite intothe delamination solution, the composite is delaminated into a coatinglayer and a metal substrate layer.

In some embodiments, the composite-delamination solution mixturefollowing delamination is screened to separate the coating layer and themetal substrate layer from the delamination solution. In someembodiments, filtration, sieving, decantation, or combinations thereofmay be used for screening of the composite-delamination solution mixturefollowing delamination.

FIG. 3 is a flow chart of an embodiment illustrating the steps of method300 for delaminating a composite as disclosed herein and its subsequentfurther processing for extraction of coating and metal substratematerials. Owing to the considerably low corrosion and dissolutiontendencies of the metal substrate in the present invention, theextracted delamination solution is not necessarily required to besubjected to purification for further reuse. The extracted delaminationsolution may be reused for delamination of other composites. This allowsthe formation of a closed-loop recovery process where materials arerepeatedly recycled and reused, and continually engage in a looparrangement, which helps create a circular economy.

In some embodiments, the recovered delaminated composite materials maybe subjected to additional separation and/or extraction process tofurther extract their respective materials contained within. In someembodiments, the recovered coating layer and metal substrate layer maybe subjected to additional separation and/or extraction processes tofurther extract the coating and metal substrate materials.

The method of the present invention is particularly applicable inachieving delamination of an electrode in batteries, wherein theelectrode is the composite, of which the electrode layer and the currentcollector are the coating and metal substrate respectively.

In some embodiments, the battery may be a primary battery or a secondarybattery. Some non-limiting examples of the battery include alkalinebattery, aluminum-air battery, lithium battery, lithium air battery,magnesium battery, solid-state battery, silver-oxide battery, zinc-airbattery, aluminum-ion battery, lead-acid battery, lithium-ion battery,magnesium-ion battery, potassium-ion battery, sodium-ion battery,sodium-air battery, silicon-air battery, zinc-ion battery andsodium-sulfur battery.

Within an electrode, a binder can be used for adhering the activematerial particles and the conductive agent together with the currentcollector to form a continuous electrical conduction path. Since thecopolymeric binder disclosed herein has excellent adhesive capability,such a copolymeric binder can be used. With good adhesive capabilityamong electrode layer components as well as between the electrode layerand the current collector, the usage of such a copolymeric binder canhelp reduce impedance and interfacial resistance between the currentcollector and electrode materials, and thereby improve ion and electrontransport rates. Furthermore, the disclosed copolymer can interactreadily with water through hydrogen bonding and ion-dipole interactions,which allows for the copolymeric binder to have excellent dispersibilityand stability in water, allowing for good processibility in forming theelectrode layer through the usage of a water-based slurry.

There are shortcomings with current methods in delaminating electrodelayers form current collectors when recycling batteries, such as therequirement of high temperatures and the release of harmful materialswhen calcination is used, or dangerous and harmful chemicals whenleaching is used.

Conversely the delamination method disclosed herein allows an electrodecomprising a current collector and an electrode layer coated on one sideor both sides of the current collector, wherein the electrode layercomprises the copolymeric binder disclosed in the invention, to beeffectively delaminated by the simple use of a delaminating solutionwithout significant safety concerns or environmental impact. Inaddition, the delamination process is highly efficient.

FIG. 4 depicts the recovered cathode layers and current collector ofExample 4 after the immersion of the double side-coated cathode into adelamination solution, wherein the cathode comprises a copolymericbinder, and wherein the delamination solution comprises sodium hydroxideof 1 M concentration and DI water. The cathode layers are shown to becompletely delaminated from the aluminum current collector, and nodiscoloration or pitting of the aluminum current collector was observed,indicating that there was no significant corrosion of the aluminumcurrent collector.

FIG. 5 depicts the recovered cathode of Comparative Example 1 whereinthe double side-coated cathode that is being immersed in thedelamination solution comprises polyvinylidene fluoride (PVDF) as thepolymeric binder. The delamination solution used herein comprises sodiumhydroxide at 0.5 M concentration and DI water. The delamination of thecathode layers from the aluminum current collector is shown to beunsuccessful where the cathode layers are still strongly adhered ontothe aluminum current collector despite being immersed into thedelamination solution. This indicates that the use of the delaminationagent disclosed in the present invention to achieve electrodedelamination is not applicable to electrode comprising non-aqueouspolymeric binders such as PVDF.

The current collector acts to collect electrons generated byelectrochemical reactions of the cathode active material or to supplyelectrons required for the electrochemical reactions. In someembodiments, the current collector can be in the form of a foil, sheetor film. In some embodiments, the current collector is a metal. In someembodiments, the current collector is selected from the group consistingof stainless steel, titanium, nickel, aluminum, copper, platinum, gold,silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc,cadmium, iron, cobalt, lead, and alloys thereof. In some embodiments,the current collector only has one layer. In some embodiments, thecurrent collector has a two-layered structure. In some embodiments, thecurrent collector has three or more layers. In some embodiments, thematerial or materials in each layer may be the same, or may be differentor partially different.

In some embodiments, when the current collector comprises more than onelayer, the current collector comprises a layer of insulating material.In some embodiments, the insulating material is a polymeric materialselected from the group consisting of polycarbonate, polyacrylate,polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane,polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyolefin,polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester),polyvinyl chloride, polyether, polyphenylene oxide, cellulose polymer,and combinations thereof. When the current collector comprises a layerof insulating material, the coating is coated onto the metal layer(s) onthe outside of the current collector.

In some embodiments, the current collector is coated with a layer ofcarbonaceous material. Such a layer of carbonaceous material would bepart of the coating layer. In some embodiments, the current collector isnot coated with a layer of carbonaceous material.

The thickness of the current collector affects the volume it occupieswithin the battery, the amount of the electrode active material needed,and hence the capacity in the battery. In some embodiments, the currentcollector has a thickness of from about 5 μm to about 50 μm, from about10 μm to about 50 μm, from about 15 μm to about 50 μm, from about 20 μmto about 50 μm, from about 25 μm to about 50 μm, from about 5 μm toabout 30 μm, from about 10 μm to about 30 μm, from about 15 μm to about30 μm, from about 20 μm to about 30 μm, from about 5 μm to about 20 μm,from about 5 μm to about 15 μm, from about 10 μm to about 30 μm, fromabout 10 μm to about 25 μm, or from about 10 μm to about 20 μm.

In some embodiments, the current collector has a thickness of less than50 μm, less than 45 μm, less than 40 μm, less than 35 μm, less than 30μm, less than 25 μm, less than 20 μm, less than 15 μm, or less than 10μm. In some embodiments, the current collector has a thickness of morethan 5 μm, more than 10 μm, more than 15 82 m, more than 20 μm, morethan 25 μm, more than 30 μm, more than 35 μm, more than 40 μm, or morethan 45 μm.

In some embodiments, the electrode may be a cathode or an anode. In someembodiments, the electrode layer further comprises an electrode activematerial.

In some embodiments, the electrode active material is a cathode activematerial, wherein the cathode active material is selected from the groupconsisting of LiCoO₂, LiNiO₂, LiNi_(x)Mn_(y)O₂, LiCo_(x)Ni_(y)O₂,Li_(1+z)Ni_(x)Mn_(y)Co_(1−x−y)O₂, LiNi_(x)Co_(y)Al_(z)O₂, LiV₂O₅,LiTiS₂, LiMoS₂, LiMnO₂, LiCrO₂, LiMn₂O₄, Li₂MnO₃, LiFeO₂, LiFePO₄, andcombinations thereof, wherein each x is independently from 0.1 to 0.9;each y is independently from 0 to 0.9; each z is independently from 0 to0.4. In certain embodiments, each x in the above general formula isindependently selected from 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25,0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525,0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8,0.825, 0.85, 0.875 and 0.9; each y in the above general formula isindependently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15,0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425,0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7,0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875 and 0.9; each z in the abovegeneral formula is independently selected from 0, 0.025, 0.05, 0.075,0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35,0.375 and 0.4. In some embodiments, each x, y and z in the above generalformula independently has a 0.01 interval.

In certain embodiments, the cathode active material is selected from thegroup consisting of LiCoO₂, LiNiO₂, LiNi_(x)Mn_(y)O₂,Li_(1+z)Ni_(x)Mn_(y)Co_(1−x−y)O₂ (NMC), LiNi_(x)Co_(y)Al_(z)O₂, LiV₂O₅,LiTiS₂, LiMoS₂, LiMnO₂, LiCrO₂, LiMn₂O₄, LiFeO₂, LiFePO₄,LiCo_(x)Ni_(y)O₂, and combinations thereof, wherein each x isindependently from 0.4 to 0.6; each y is independently from 0.2 to 0.4;and each z is independently from 0 to 0.1. In other embodiments, thecathode active material is not LiCoO₂, LiNiO₂, LiV₂O₅, LiTiS₂, LiMoS₂,LiMnO₂, LiCrO₂, LiMn₂O₄, LiFeO₂, or LiFePO₄. In further embodiments, thecathode active material is not LiNi_(x)Mn_(y)O₂,Li_(1+z)Ni_(x)Mn_(y)Co_(1−x−y)O₂, LiNi_(x)Co_(y)Al_(z)O₂ orLiCo_(x)Ni_(y)O₂, wherein each x is independently from 0.1 to 0.9; eachy is independently from 0 to 0.45; and each z is independently from 0 to0.2. In certain embodiments, the cathode active material isLi_(1+x)Ni_(a)Mn_(b)Co_(c)Al_((1-a-b-c))O₂; wherein −0.2≤x≤0.2, 0≤a<1,0≤b<1, 0>c<1, and a+b+c≤1. In some embodiments, the cathode activematerial has the general formulaLi_(1+x)Ni_(a)Mn_(b)Co_(c)Al_(1−a−b−c))O₂, with 0.33≤a≤0.92, 0.33≤a≤0.9,0.33≤a≤0.8, 0.4≤a≤0.92, 0.4≤a≤0.9, 0.4≤a<0.8, 0.5≤a≤0.92, 0.5≤a≤0.9,0.5≤a≤0.8, 0.6≤a≤0.92, or 0.6≤a≤0.9; 0≤b≤0.5, 0≤b≤0.4, 0≤b≤0.3, 0≤b≤0.2,0.1≤b≤0.5, 0.1≤b≤0.4, 0.1≤b≤0.3, 0.1≤b≤0.2, 0.2≤b≤0.5, 0.2≤b≤0.4, or0.2≤b≤0.3; 0≤c≤0.5, 0≤c≤0.4, 0≤c≤0.3, 0.1≤c≤0.5, 0.1≤c≤0.4, 0.1≤c≤0.3,0.1≤c≤0.2, 0.2≤c≤0.5, 0.2≤c≤0.4, or 0.2≤c≤0.3. In some embodiments, thecathode active material has the general formula LiMPO4, wherein M isselected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti,La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In someembodiments, the cathode active material is selected from the groupconsisting of LiFePO₄, LiCoPO₄, LiNiPO₄, LiMnPO₄, LiMnFePO₄,LiMn_(x)Fe_((1-x))PO₄, and combinations thereof; wherein 0<x<1. In someembodiments, the cathode active material is LiNi_(x)Mn_(y)O₄; wherein0.1≤x≤0.9 and 0≤y≤2. In certain embodiments, the cathode active materialis xLi₂MnO₃·(1-x)LiMO₂, wherein M is selected from the group consistingof Ni, Co, Mn, and combinations thereof; and wherein 0<x<1. In someembodiments, the cathode active material is Li₃V₂(PO₄)₃, or LiVPO₄F. Incertain embodiments, the cathode active material has the general formulaLi₂MSiO₄, wherein M is selected from the group consisting of Fe, Co, Mn,Ni, and combinations thereof.

In certain embodiments, the cathode active material is doped with adopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F,Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, andcombinations thereof. In some embodiments, the dopant is not Co, Cr, V,Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge. Incertain embodiments, the dopant is not Al, Sn, or Zr.

In some embodiments, the cathode active material isLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ (NMC333), LiNi_(0.4)Mn_(0.4)Co_(0.2)O₂,LiNi_(0.5)Mn_(0.3)Co_(0.2)O₂ (NMC532), LiNi_(0.6)Mn_(0.2)Co_(0.2)O₂(NMC622), LiNi_(0.7)Mn_(0.15)Co_(0.15)O₂, LiNi_(0.7)Mn_(0.1)Co_(0.2)O₂,LiNi_(0.8)Mn_(0.1)Co_(0.1)O₂ (NMC811), LiNi_(0.92)Mn_(0.04)Co_(0.04)O₂,LiNi_(0.8)Co_(0.15)Al_(0.05)O₂ (NCA), LiNiO₂ (LNO), or combinationsthereof.

In other embodiments, the cathode active material is not LiCoO₂, LiNiO₂,LiMnO₂, LiMn₂O₄, or Li₂MnO₃. In further embodiments, the cathode activematerial is not LiNi_(0.33)Mn_(0.33)Co_(0.33)O₂,LiNi_(0.4)Mn_(0.4)Co_(0.2)O₂, LiNi_(0.5)Mn_(0.3)Co_(0.2)O₂,LiNi_(0.6)Mn_(0.2)Co_(0.2)O₂, LiNi_(0.7)Mn_(0.15)Co_(0.15)O₂,LiNi_(0.7)Mn_(0.1)Co_(0.2)O₂, LiNi_(0.8)Mn_(0.1)Co_(0.1)O₂,LiNi_(0.92)Mn_(0.04)Co_(0.04)O₂, or LiNi_(0.8)Co_(0.15)Al_(0.05)O₂.

In certain embodiments, the cathode active material comprises or is acore-shell composite having a core and shell structure, wherein the coreand the shell each independently comprise a lithium transition metaloxide selected from the group consisting ofLi_(1+x)Ni_(a)Mn_(b)Co_(c)Al_((1-a-b-c))O₂, LiCoO₂, LiNiO₂, LiMnO₂,LiMn₂O₄, Li₂MnO₃, LiCrO₂, Li₄Ti₅O₁₂, LiV₂O₅, LiTiS₂, LiMoS₂,LiCo_(a)Ni_(b)O₂, LiMn_(a)Ni_(b)O₂, and combinations thereof; wherein−0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1. In certain embodiments,each x in the above general formula is independently selected from −0.2,−0.175, −0.15, −0.125, −0.1, −0.075, −0.05, −0.025, 0, 0.025, 0.05,0.075, 0.1, 0.125, 0.15, 0.175 and 0.2; each a in the above generalformula is independently selected from 0, 0.025, 0.05, 0.075, 0.1,0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375,0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65,0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925,0.95 and 0.975; each b in the above general formula is independentlyselected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2,0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475,0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75,0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975; each c inthe above general formula is independently selected from 0, 0.025, 0.05,0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325,0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6,0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875,0.9, 0.925, 0.95 and 0.975. In some embodiment, each x, a, b and c inthe above general formula independently has a 0.01 interval. In otherembodiments, the core and the shell each independently comprise two ormore lithium transition metal oxides. In some embodiments, one of thecore or shell comprises only one lithium transition metal oxide, whilethe other comprises two or more lithium transition metal oxides. Thelithium transition metal oxide or oxides in the core and the shell maybe the same, or they may be different or partially different. In someembodiments, the two or more lithium transition metal oxides areuniformly distributed over the core. In certain embodiments, the two ormore lithium transition metal oxides are not uniformly distributed overthe core. In some embodiments, the cathode active material is not acore-shell composite.

In some embodiments, each of the lithium transition metal oxides in thecore and the shell is independently doped with a dopant selected fromthe group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al,Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. Incertain embodiments, the core and the shell each independently comprisetwo or more doped lithium transition metal oxides. In some embodiments,the two or more doped lithium transition metal oxides are uniformlydistributed over the core and/or the shell. In certain embodiments, thetwo or more doped lithium transition metal oxides are not uniformlydistributed over the core and/or the shell.

In some embodiments, the cathode active material comprises or is acore-shell composite comprising a core comprising a lithium transitionmetal oxide and a shell comprising a transition metal oxide. In certainembodiments, the lithium transition metal oxide is selected from thegroup consisting of Li_(1+x)Ni_(a)Mn_(b)Co_(c)Al_((1-a-b-c))O₂, LiCoO₂,LiNiO₂, LiMnO₂, LiMn₂O₄, Li₂MnO₃, LiCrO₂, Li₄Ti₅O₁₂, LiV₂O₅, LiTiS₂,LiMoS₂, LiCo_(a)Ni_(b)O₂, LiMn_(a)Ni_(b)O₂, and combinations thereof;wherein −0.2≤x<0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c<1. In certainembodiments, x in the above general formula is independently selectedfrom −0.2, −0.175, −0.15, −0.125, −0.1, −0.075, −0.05, −0.025, 0, 0.025,0.05, 0.075, 0.1, 0.125, 0.15, 0.175 and 0.2; each a in the abovegeneral formula is independently selected from 0, 0.025, 0.05, 0.075,0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35,0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625,0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9,0.925, 0.95 and 0.975; each b in the above general formula isindependently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15,0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425,0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7,0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975;each c in the above general formula is independently selected from 0,0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275,0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55,0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825,0.85, 0.875, 0.9, 0.925, 0.95 and 0.975. In some embodiment, each x, a,b and c in the above general formula independently has a 0.01 interval.In some embodiments, the transition metal oxide is selected from thegroup consisting of Fe₂O₃, MnO₂, Al₂O₃, MgO, ZnO, TiO₂, La₂O₃, CeO₂,SnO₂, ZrO₂, RuO₂, and combinations thereof. In certain embodiments, theshell comprises a lithium transition metal oxide and a transition metaloxide.

In some embodiments, the diameter of the core is from about 1 μm toabout 15 μm, from about 3 μm to about 15 μm, from about 3 μm to about 10μm, from about 5 μm to about 10 μm, from about 5 μm to about 45 μm, fromabout 5 μm to about 35 μm, from about 5 μm to about 25 μm, from about 10μm to about 45 μm, from about 10 μm to about 40 μm, from about 10 μm toabout 35 μm, from about 10 μm to about 25 μm, from about 15 μm to about45 μm, from about 15 μm to about 30 μm, from about 15 μm to about 25 μm,from about 20 μm to about 35 μm, or from about 20 μm to about 30 μm. Incertain embodiments, the thickness of the shell is from about 1μm toabout 45 μm, from about 1 μm to about 35 inn, from about 1μm to about 25inn, from about 1μm to about 15 μm, from about 1μm to about 10 inn, fromabout 1 μm to about 5μm, from about 3μm to about 15 μm, from about 3μmto about 10 inn, from about 5μm to about 10 μm, from about 10 μm toabout 35 μm, from about 10 μm to about 20 inn, from about 15 μm to about30 μm, from about 15 μm to about 25 μm, or from about 20 μm to about 35inn. In certain embodiments, the diameter or thickness ratio of the coreand the shell are in the range of 15:85 to 85:15, 25:75 to 75:25, 30:70to 70:30, or 40:60 to 60:40. In certain embodiments, the volume orweight ratio of the core and the shell is 95:5, 90:10, 80:20, 70:30,60:40, 50:50, 40:60, or 30:70.

In some embodiments, the electrode active material is an anode activematerial, wherein the anode active material is selected the groupconsisting of natural graphite particulate, synthetic graphiteparticulate, hard carbon, soft carbon, mesocarbon microbeads (MCMB), Snparticulate, SnO₂, SnO, Li₄Ti₅O₁₂ particulate, Si particulate, Si—Ccomposite particulate, and combinations thereof.

In certain embodiments, the anode active material is doped with ametallic element or a nonmetal element. In some embodiments, themetallic element is selected from the group consisting of Fe, Ni, Mn,Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, and combinations thereof. In someembodiments, the nonmetal element is B, Si, Ge, N, P, F, S, Cl, I, Se,or combinations thereof.

In some embodiments, the anode active material comprises or is acore-shell composite having a core and shell structure, wherein the coreand the shell each is independently selected from the group consistingof natural graphite particulate, synthetic graphite particulate, hardcarbon, soft carbon, mesocarbon microbeads (MCMB), Sn particulate, SnO₂,SnO, Li₄Ti₅O₁₂ particulate, Si particulate, Si—C composite particulate,and combinations thereof.

In certain embodiments, the core-shell composite comprises a corecomprising a carbonaceous material and a shell coated on thecarbonaceous material core. In some embodiments, the carbonaceousmaterial is selected from the group consisting of soft carbon, hardcarbon, natural graphite particulate, synthetic graphite particulate,mesocarbon microbeads, Kish graphite, pyrolytic carbon, mesophasepitches, mesophase pitch-based carbon fiber, and combinations thereof.In certain embodiments, the shell is selected from the group consistingof natural graphite particulate, synthetic graphite particulate, hardcarbon, soft carbon, mesocarbon microbeads (MCMB), Sn particulate, SnO₂,SnO, Li₄Ti₅O₁₂ particulate, Si particulate, Si—C composite particulate,and combinations thereof.

In certain embodiments, the anode active material is not doped with ametallic element or a nonmetal element. In some embodiments, the anodeactive material is not doped with Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce,Sn, Zr, Ru, B, Si, Ge, N, P, F, S, Cl, I, or Se.

In some embodiments, the electrode layer may additionally comprise otheradditives for enhancing electrode properties. In some embodiments, theadditives may include conductive agents, surfactants, dispersants andflexibility enhancement additives.

In some embodiments, the electrode layer further comprises a conductiveagent. The conductive agent is for enhancing the electrically-conductingproperty of an electrode. Any suitable material can act as theconductive agent. In some embodiments, the conductive agent is acarbonaceous material. Some non-limiting examples include carbon, carbonblack, graphite, expanded graphite, graphene, graphene nanoplatelets,carbon fibers, carbon nano-fibers, graphitized carbon flake, carbontubes, activated carbon, Super P, 0-dimensional KS6, 1-dimensional vaporgrown carbon fibers (VGCF), mesoporous carbon, and combinations thereof.

In some embodiments, the electrode layer further comprises a lithiumsalt. The lithium salt can help increase ionic conductivity of theelectrode layer and thereby reduce the resistance of the electrode. Insome embodiments, the lithium salt is selected from the group consistingof lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithiumhexafluorophosphate (LiPF₆), lithium fluoroborate (LiBF₄), lithiummetaborate (LiBO₂), lithium perchlorate (LiClO₄), lithium nitrate(LiNO₃), lithium bis(fluorosulfonyl)imide (LiFSI), lithium iodide (LiI),lithium tetrachloroaluminate (LiAlCl₄), lithium difluoro(oxalate)borate(LiBF₂C₂O₄), lithium bis(oxalato)borate (LiBOB), lithium acetate (LiAc),and combinations thereof.

In some embodiments, the electrode layer further comprises anion-conductive polymer. The ion-conductive polymer can help increaseionic conductivity of the electrode layer and thereby reduce theresistance of the electrode. In some embodiments, the ion-conductivepolymer is selected from the group consisting of polyethers,polycarbonates, polyacrylates, polysiloxanes, polyphosphazenes,polyethylene derivatives, alkylene oxide derivatives, phosphatepolymers, poly-lysines, polyester sulfides, polyvinyl alcohol,polyvinylidene fluoride, polymers containing one or more ionicallydissociable groups, copolymers thereof, and combinations thereof. Insome embodiments, the ion-conductive polymer is selected from the groupconsisting of polyacrylonitriles (PANs), polyethylene carbonates (PECs),polyacrylamides (PAMs), polyethylene glycols (PEGs), polyethylene oxides(PEOs), polyhydroxyethylmethacrylates (P(HEMAs)), polyphosphonates(PPhs), polysiloxanes, polyamides (PAs), polydilactones, polydiesters,polyphasphazenes (PPHOSs), polyurethanes (PUs), copolymers thereof, andcombinations thereof.

In some embodiments, the electrode layer further comprises an inorganicsolid-state electrolyte. The inorganic solid-state electrolyte can helpincrease ionic conductivity of the electrode layer and thereby reducethe resistance of the electrode. In some embodiments, the inorganicsolid-state electrolyte is selected from the group consisting of LPSsulfides containing sulfur and phosphorus, for example, Li₂S—P₂S₅;Li_(4-x)Ge_(1−x)P_(x)S₄ (LGPS, x is 0.1 to 2); Li_(10±1)MP₂X₁₂ (M=Ge,Si, Sn, Al, X =S, Se); Li_(3.833) Sn_(0.833)As_(0.166)S₄; Li₄SnS₄;B₂S₃—Li₂S; x Li₂S-(100-x) P₂S₅ (x is 70 to 80); Li₂S—SiS₂—Li₃N;Li₂S—P₂S₅—LiI; Li₂S—SiS₂—LiI; Li₂S—B₂S₃-LiI; Li₁₀SnP₂S₁₂; Li₆PS₅XArgyrodite (where X is a halogen); thio-LISICON compounds such asLi_(3.25)Ge_(0.25)P_(0.75)S₄; anti-perovskites such as Li₃SX (X is Cl orBr); lithium-phosphorus-iodine-oxygen sulfides;lithium-phosphorus-oxygen sulfides; lithium-zinc-germanium sulfides;lithium-germanium-sulfides; LLTO-based compounds such as (La, Li) TiO₃;Li₆La₂CaTa₆O₁₂; Li₆La₂ANb₂O₁₂ (A is Ca and/or Sr); Li₂Nd₃TeSbO₁₂;Li₃BO_(2.5)N_(0.5); Li₉SiAlO₈; LAGP compounds(Li_(1+x)Al_(x)Ge_(2-x)(PO₄)₃, where 0≤x≤1, 0≤y≤1); Li₂O—LATP compoundssuch as Al₂O₃—TiO₂—P₂O₅; Li_(1+x)Al_(x)Ti_(2-x)(PO₄)₃ (where 0≤x≤1,0≤y≤1); Li_(1+x)Ti_(2−x)Al_(x)Si_(y)(PO₄)_(3−y) (where 0≤x≤1, 0≤y≤1);LiAl_(x)Zr_(2−x)(PO₄)₃ (where 0≤x≤1, 0≤y≤1); LiTi_(x)Zr_(2−x)(PO₄)₃(where 0≤x≤1, 0≤y≤1); LISICON type solid-state electrolytes; LIPONcompounds (Li_(3+y)PO_(4−x)N_(x), where 0≤x≤1, 0≤y≤1); Perovskitecompounds ((La, Li) TiO₃); NASICON compounds such as LiTi₂(PO₄)₃;anti-perovskites such as Li3OX (X is Cl or Br);lithium-aluminum-titanium-silicon phosphates (LATSP); lithium-aluminumoxides; lithium-vanadium-germanium oxides; lithium-zinc-germaniumoxides; lithium-stuffed garnets such as lithium-lanthanum-zirconiumoxides; lithium-lanthanum-zirconium-aluminum oxides;lithium-lanthanum-zirconium-tantalum oxides; Li₃N; lithium-aluminumchlorides; and combinations thereof.

The copolymeric binder applied in the present invention exhibits strongadhesion to the current collector. It is important for the copolymericbinder to have good adhesive strength to the current collector as itpromotes the binding force of the electrode layer to the currentcollector in the making of battery electrode, prevents separation andenhances the mechanical stability of the electrode. In some embodiments,the adhesive strength between the copolymeric binder and the currentcollector is from about 2 N/cm to about 6 N/cm, from about 2 N/cm toabout 5.8 N/cm, from about 2 N/cm to about 5.6 N/cm, from about 2 N/cmto about 5.4 N/cm, from about 2 N/cm to about 5.2 N/cm, from about 2N/cm to about 5 N/cm, from about 2 N/cm to about 4.8 N/cm, from about 2N/cm to about 4.6 N/cm, from about 2 N/cm to about 4.4 N/cm, from about2 N/cm to about 4.2 N/cm, from about 2 N/cm to about 4 N/cm, from about2 N/cm to about 3.9 N/cm, from about 2 N/cm to about 3.8 N/cm, fromabout 2 N/cm to about 3.7 N/cm, from about 2 N/cm to about 3.6 N/cm,from about 2 N/cm to about 3.5 N/cm, from about 2 N/cm to about 3.4N/cm, from about 2 N/cm to about 3.3 N/cm, from about 2 N/cm to about3.2 N/cm, from about 2 N/cm to about 3.1 N/cm, from about 2 N/cm toabout 3 N/cm, from about 2.1 N/cm to about 6 N/cm, from about 2.2 N/cmto about 6 N/cm, from about 2.3 N/cm to about 6 N/cm, from about 2.4N/cm to about 6 N/cm, from about 2.5 N/cm to about 6 N/cm, from about2.6 N/cm to about 6 N/cm, from about 2.7 N/cm to about 6 N/cm, fromabout 2.8 N/cm to about 6 N/cm, from about 2.9 N/cm to about 6 N/cm,from about 3 N/cm to about 6 N/cm, from about 3.1 N/cm to about 6 N/cm,from about 3.2 N/cm to about 6 N/cm, from about 3.3 N/cm to about 6N/cm, from about 3.4 N/cm to about 6 N/cm, from about 3.5 N/cm to about6 N/cm, from about 3.6N/cm to about 6 N/cm, from about 3.7 N/cm to about6 N/cm, from about 3.8 N/cm to about 6 N/cm, from about 3.9 N/cm toabout 6 N/cm, from about 4 N/cm to about 6 N/cm, from about 2.5 N/cm toabout 5.5 N/cm, from about 2.5 N/cm to about 5 N/cm, from about 2.5 N/cmto about 4.5 N/cm, from about 2.5 N/cm to about 4 N/cm, from about 2.5N/cm to about 3.5 N/cm, from about 3 N/cm to about 5 N/cm, from about2.2 N/cm to about 4.2 N/cm or from about 2.2 N/cm to about 5.2 N/cm.

In some embodiments, the adhesive strength between the copolymericbinder and the current collector is less than 6 N/cm, less than 5.8N/cm, less than 5.6 N/cm, less than 5.4 N/cm, less than 5.2 N/cm, lessthan 5 N/cm, less than 4.8 N/cm, less than 4.6 N/cm, less than 4.4 N/cm,less than 4.2 N/cm, less than 4 N/cm, less than 3.9 N/cm, less than 3.8N/cm, less than 3.7 N/cm, less than 3.6 N/cm, less than 3.5 N/cm, lessthan 3.4 N/cm, less than 3.3 N/cm, less than 3.2 N/cm, less than 3.1N/cm, less than 3 N/cm, less than 2.9 N/cm, less than 2.8 N/cm, lessthan 2.7 N/cm, less than 2.6 N/cm, less than 2.5 N/cm, less than 2.4N/cm, less than 2.3 N/cm or less than 2.2 N/cm. In some embodiments, theadhesive strength between the copolymeric binder and the currentcollector is more than 2 N/cm, more than 2.1 N/cm, more than 2.2 N/cm,more than 2.3 N/cm, more than 2.4 N/cm, more than 2.5 N/cm, more than2.6 N/cm, more than 2.7 N/cm, more than 2.8 N/cm, more than 2.9 N/cm,more than 3 N/cm, more than 3.1 N/cm, more than 3.2 N/cm, more than 3.3N/cm, more than 3.4 N/cm, more than 3.5 N/cm, more than 3.6 N/cm, morethan 3.7 N/cm, more than 3.8 N/cm, more than 3.9 N/cm, more than 4 N/cm,more than 4.2 N/cm, more than 4.4 N/cm, more than 4.6 N/cm, more than4.8 N/cm, more than 5 N/cm, more than 5.2 N/cm, more than 5.4 N/cm, morethan 5.6 N/cm or more than 5.8 N/cm.

In addition, the copolymeric binder applied in the present inventionallows the exhibition of strong adhesion of the electrode layer to thecurrent collector in an electrode. It is important for the electrodelayer to have good peeling strength to the current collector as thiswould greatly influence the mechanical stability of the electrodes andthe cyclability of the battery. Therefore, the electrodes should havesufficient peeling strength to withstand the rigors of batterymanufacture.

In some embodiments, the peeling strength between the current collectorand the electrode layer is in the range from about 1.0 N/cm to about 8.0N/cm, from about 1.0 N/cm to about 6.0 N/cm, from about 1.0 N/cm toabout 5.0 N/cm, from about 1.0 N/cm to about 4.0 N/cm, from about 1.0N/cm to about 3.0 N/cm, from about 1.0 N/cm to about 2.5 N/cm, fromabout 1.0 N/cm to about 2.0 N/cm, from about 1.2 N/cm to about 3.0 N/cm,from about 1.2 N/cm to about 2.5 N/cm, from about 1.2 N/cm to about 2.0N/cm, from about 1.5 N/cm to about 3.0 N/cm, from about 1.5 N/cm toabout 2.5 N/cm, from about 1.5 N/cm to about 2.0 N/cm from about 1.8N/cm to about 3.0 N/cm, from about 1.8 N/cm to about 2.5 N/cm, fromabout 2.0 N/cm to about 6.0 N/cm, from about 2.0 N/cm to about 5.0 N/cm,from about 2.0 N/cm to about 3.0 N/cm, from about 2.0 N/cm to about 2.5N/cm, from about 2.2 N/cm to about 3.0 N/cm, from about 2.5 N/cm toabout 3.0 N/cm, from about 3.0 N/cm to about 8.0 N/cm, from about 3.0N/cm to about 6.0 N/cm, or from about 4.0 N/cm to about 6.0 N/cm.

In some embodiments, the peeling strength between the current collectorand the electrode layer is 1.0 N/cm or more, 1.2 N/cm or more, 1.5 N/cmor more, 2.0 N/cm or more, 2.2 N/cm or more, 2.5 N/cm or more, 3.0 N/cmor more, 3.5 N/cm or more, 4.5 N/cm or more, 5.0 N/cm or more, 5.5 N/cmor more, 6.0 N/cm or more, 6.5 N/cm or more, 7.0 N/cm or more or 7.5N/cm or more. In some embodiments, the peeling strength between thecurrent collector and the electrode layer is less than 8.0 N/cm, lessthan 7.5 N/cm, less than 7.0 N/cm, less than 6.5 N/cm, less than 6.0N/cm, less than 5.5 N/cm, less than 5.0 N/cm, less than 4.5 N/cm, lessthan 4.0 N/cm, less than 3.5 N/cm, less than 3.0 N/cm, less than 2.8N/cm, less than 2.5 N/cm, less than 2.2 N/cm, less than 2.0 N/cm, lessthan 1.8 N/cm, or less than 1.5 N/cm.

In some embodiments, the surface density of each of the cathode andanode electrode layer is independently from about 1 mg/cm² to about 50mg/cm², from about 2.5 mg/cm² to about 50 mg/cm², from about 5 mg/cm² toabout 50 mg/cm², from about 7.5 mg/cm² to about 50 mg/cm², from about 10mg/cm² to about 50 mg/cm², from about 12.5 mg/cm² to about 50 mg/cm²,from about 15 mg/cm² to about 50 mg/cm², from about 17.5 mg/cm² to about50 mg/cm², from about 20 mg/cm² to about 50 mg/cm², from about 25 mg/cm²to about 50 mg/cm², from about 30 mg/cm² to about 50 mg/cm², from about1 mg/cm² to about 30 mg/cm², from about 2.5 mg/cm² to about 30 mg/cm²,from about 5 mg/cm² to about 30 mg/cm², from about 7.5 mg/cm² to about30 mg/cm², from about 10 mg/cm² to about 30 mg/cm², from about 12.5mg/cm² to about 30 mg/cm², from about 15 mg/cm² to about 30 mg/cm², fromabout 17.5 mg/cm² to about 30 mg/cm², from about 20 mg/cm² to about 30mg/cm², from about 1 mg/cm² to about 20 mg/cm², from about 2.5 mg/cm² toabout 20 mg/cm², from about 5 mg/cm² to about 20 mg/cm², from about 7.5mg/cm² to about 20 mg/cm², from about 10 mg/cm² to about 20 mg/cm², fromabout 12.5 mg/cm² to about 20 mg/cm², from about 1 mg/cm² to about 15mg/cm², from about 2.5 mg/cm² to about 15 mg/cm², from about 5 mg/cm² toabout 15 mg/cm², from about 7.5 mg/cm² to about 15 mg/cm², or from about10 mg/cm² to about 15 mg/cm².

In some embodiments, the surface density of each of the cathode andanode electrode layer is independently less than 50 mg/cm², less than 45mg/cm², less than 35 mg/cm², less than 30 mg/cm², less than 25 mg/cm²,less than 20 mg/cm², less than 17.5 mg/cm², less than 15 mg/cm², lessthan 12.5 mg/cm², less than 10 mg/cm², less than 7.5 mg/cm², less than 5mg/cm², or less than 2.5 mg/cm². In some embodiments, the surfacedensity of each of the cathode and anode electrode layer isindependently more than 1 mg/cm², more than 2.5 mg/cm², more than 5mg/cm², more than 7.5 mg/cm², more than 10 mg/cm², more than 12.5mg/cm², more than 15 mg/cm², more than 17.5 mg/cm², more than 20 mg/cm²,more than 25 mg/cm², more than 30 mg/cm², more than 35 mg/cm², or morethan 40 mg/cm².

In some embodiments, the density of each of the cathode and anodeelectrode layer is independently from about 0.5 g/cm³ to about 7.5g/cm³, from about 1 g/cm³ to about 7.5 g/cm³, from about 1.5 g/cm³ toabout 7.5 g/cm³, from about 2 g/cm³ to about 7.5 g/cm³, from about 2.5g/cm³ to about 7.5 g/cm³, from about 3 g/cm³ to about 7.5 g/cm³, fromabout 3.5 g/cm³ to about 7.5 g/cm³, from about 4 g/cm³ to about 7.5g/cm³, from about 4.5 g/cm³ to about 7.5 g/cm³, from about 5 g/cm³ toabout 7.5 g/cm3, from about 0.5 g/cm³ to about 5 g/cm³, from about 1g/cm³ to about 5 g/cm³, from about 1.5 g/cm³ to about 5 g/cm³, fromabout 2 g/cm³ to about 5 g/cm³, from about 2.5 g/cm³ to about 5 g/cm³,from about 3 g/cm³ to about 5 g/cm³, from about 0.5 g/cm³ to about 2.5g/cm³, from about 1 g/cm³ to about 2.5 g/cm³, or from about 1.5 g/cm³ toabout 2.5 g/cm³.

In some embodiments, the density of each of the cathode and anodeelectrode layer is independently less than 7.5 g/cm³, less than 7 g/cm³,less than 6.5 g/cm³, less than 6 g/cm³, less than 5.5 g/cm³, less than 5g/cm³, less than 4.5 g/cm³, less than 4 g/cm³, less than 3.5 g/cm³, lessthan 3 g/cm³, less than 2.5 g/cm³, less than 2 g/cm³, or less than 1.5g/cm³. In some embodiments, the density of each of the cathode and anodeelectrode layer is independently more than 0.5 g/cm³, more than 1 g/cm³,more than 1.5 g/cm³, more than 2 g/cm³, more than 2.5 g/cm³, more than 3g/cm³, more than 3.5 g/cm³, more than 4 g/cm³, more than 4.5 g/cm³, morethan 5 g/cm³, more than 5.5 g/cm³, more than 6 g/cm³, or more than 6.5g/cm³.

In some embodiments, a battery comprising an electrode that is to bedelaminated is first disassembled into one or more battery pieces,wherein said one or more battery pieces comprise one or more electrodepieces. There is no particular limitation on the method used todisassemble the battery, except that the minimum size of the resultantbattery pieces should be larger than the hole size of the screen usedfor screening of the composite-delamination solution mixture followingdelamination in order to ensure that the pieces would be able to bescreened. In some embodiments, a crusher, mill, or cutter is used todisassemble the battery. In some embodiments, a water jet is used todisassemble the battery. In some embodiments, low temperature treatmentof the battery, for example using liquid nitrogen, is conducted beforedisassembly. In some embodiments, the battery is first discharged. Insome embodiments, the battery is discharged by immersion in a saltsolution. In other embodiments, when a water jet is used fordisassembling the battery, and/or when low temperature treatment of thebattery is conducted before battery disassembly, discharging of thebattery is not required.

In some embodiments, when the battery pieces are immersed into thedelamination solution to achieve delamination of the electrodes, theweight ratio of the battery pieces to the delamination solution is fromabout 0.01% to about 50%, from about 0.02% to about 50%, from about0.05% to about 50%, from about 0.1% to about 50%, from about 0.2% toabout 50%, from about 0.5% to about 50%, from about 1% to about 50%,from about 2% to about 50%, from about 5% to about 50%, from about 10%to about 50%, from about 15% to about 50%, from about 20% to about 50%,from about 25% to about 50%, from about 30% to about 50%, from about0.01% to about 25%, from about 0.02% to about 25%, from about 0.05% toabout 25%, from about 0.1% to about 25%, from about 0.2% to about 25%,from about 0.5% to about 25%, from about 1% to about 25%, from about 2%to about 25%, from about 5% to about 25%, from about 10% to about 25%,from about 0.1% to about 15%, from about 0.2% to about 15%, from about0.5% to about 15%, from about 1% to about 15%, from about 2% to about15%, from about 5% to about 15%, from about 0.1% to about 5%, from about0.2% to about 5%, from about 0.5% to about 5%, from about 1% to about5%, or from about 2% to about 5%.

In some embodiments, when the battery pieces are immersed into thedelamination solution to achieve delamination of the electrodes, theweight ratio of the battery pieces to the delamination solution is lessthan 50%, less than 45%, less than 40%, less than 35%, less than 30%,less than 25%, less than 20%, less than 15%, less than 10%, less than5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, lessthan 0.1%, or less than 0.05%. In some embodiments, when the batterypieces are immersed into the delamination solution to achievedelamination of the electrodes, the weight ratio of the battery piecesto the delamination solution is more than 0.01%, more than 0.02%, morethan 0.05%, more than 0.1%, more than 0.2%, more than 0.5%, more than1%, more than 2%, more than 5%, more than 10%, more than 15%, more than20%, more than 25%, more than 30%, more than 35%, or more than 40%.

In other embodiments, the electrode piece(s) is separated from theremainder of the battery piece(s) following disassembly but prior todelamination. In some embodiments, following separation of the electrodepiece(s) from the remainder of the battery piece(s), only the electrodepiece(s) are subjected to delamination.

In some embodiments, when only the electrode pieces are immersed intothe delamination solution to achieve delamination of the electrodes, theweight ratio of the electrode pieces to the delamination solution isfrom about 0.01% to about 50%, from about 0.02% to about 50%, from about0.05% to about 50%, from about 0.1% to about 50%, from about 0.2% toabout 50%, from about 0.5% to about 50%, from about 1% to about 50%,from about 2% to about 50%, from about 5% to about 50%, from about 10%to about 50%, from about 15% to about 50%, from about 20% to about 50%,from about 25% to about 50%, from about 30% to about 50%, from about0.01% to about 25%, from about 0.02% to about 25%, from about 0.05% toabout 25%, from about 0.1% to about 25%, from about 0.2% to about 25%,from about 0.5% to about 25%, from about 1% to about 25%, from about 2%to about 25%, from about 5% to about 25%, from about 10% to about 25%,from about 0.1% to about 15%, from about 0.2% to about 15%, from about0.5% to about 15%, from about 1% to about 15%, from about 2% to about15%, from about 5% to about 15%, from about 0.1% to about 5%, from about0.2% to about 5%, from about 0.5% to about 5%, from about 1% to about5%, or from about 2% to about 5%.

In some embodiments, when only the electrode pieces are immersed intothe delamination solution to achieve delamination of the electrodes, theweight ratio of the electrode pieces to the delamination solution isless than 50%, less than 45%, less than 40%, less than 35%, less than30%, less than 25%, less than 20%, less than 15%, less than 10%, lessthan 5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%,less than 0.1%, or less than 0.05%. In some embodiments, when only theelectrode pieces are immersed into the delamination solution to achievedelamination of the electrodes, the weight ratio of the electrode piecesto the delamination solution is more than 0.01%, more than 0.02%, morethan 0.05%, more than 0.1%, more than 0.2%, more than 0.5%, more than1%, more than 2%, more than 5%, more than 10%, more than 15%, more than20%, more than 25%, more than 30%, more than 35%, or more than 40%.

The utilization of the method of the present invention in delaminatingan electrode comprising a copolymeric binder results in a delaminationsuccess rate of greater than 75%, an exceptionally high recovery rate(>97%), and a short time required to delaminate the electrode layer fromthe current collector (<180 s).

In some embodiments, delamination of the electrode occurs along theelectrode layer-current collector interface. The delamination successrate refers to the extent of delamination of electrode layer from thecurrent collector. Success rate can be calculated by the formula

${{success}{{rate}{}(\%)}} = {\frac{{mass}{of}{electrode}{layer}{successfully}{delaminated}}{\begin{matrix}{{{mass}{of}{electrode}{layer}{successfully}{delaminated}} +} \\{{mass}{of}{electrode}{layer}{remaining}{on}{current}{collector}}\end{matrix}} \times 100\%}$

Following the delamination reaction, the mass of the electrode layerpresent in the delamination solution would correspond to the mass ofelectrode layer successfully delaminated. The mass of the electrodelayer still coated on the current collector is then the mass ofelectrode layer remaining on the current collector, and can be measuredby scraping this remaining electrode layer off manually, then weighingthe mass of the scraped contents. In the case of the present inventionwhere an electrode layer is completely delaminated from the currentcollector, the delamination success rate is 100%. In other cases wherean electrode layer is not delaminated from the current collector or anelectrode layer is partially delaminated from the current collector withvisible deposits of the electrode layer remaining on the currentcollector, the success rate would then be less than 100%.

The recovery rate refers to the proportion of the sum of the weight ofthe recovered electrode layer and current collector successfullyretrieved, based on the initial weight of electrode before immersioninto the delamination solution. The recovery rate is only calculatedwhen the success rate is greater than 75%, since below this quantity, itis assumed that the delamination is ineffective, and would not beeconomically feasible so as to be worth considering in an industrialcontext. It serves as a reflection of the extent of corrosion ofinvaluable metal materials in the electrode and/or dissolution of theinvaluable metal materials into the delamination solution. The methoddisclosed herein yields a high recovery rate, indicating that extent ofcorrosion or dissolution of metallic electrode materials, such as thecurrent collector, into the delamination solution is negligible.

The present invention provides a simple method that can be used todelaminate the electrode layer from the current collector, taking intoaccount the composition of the copolymeric binder used. As separation ofelectrode layers and current collectors constitutes a vital step in therecycling of batteries, the method disclosed herein offers a technicalsolution in fulfilling the demand in battery recycling. The method ofthe present invention circumvents both complex separation processes andcontamination of current collector, and enables an excellent materialsrecovery (i.e. high recovery rate).

The method disclosed in the present invention considerably reduces thetime required to delaminate the electrode layer from the currentcollector in a battery without damaging the underlying currentcollector. With a shorter contact time between the electrode and thedelamination solution, corrosion of current collector and electrodeactive material, as well as other electrode materials made of metals,could be circumvented. For example, the shorter contact time allows thenatural oxide layer formed on the surface of the aluminum currentcollector to achieve sufficient protection against corrosion when anelectrode comprising an aluminum current collector is immersed into astrong base-containing delamination solution.

The method of the present invention is also applicable to achievedelamination of a packaging material by immersing the packaging materialinto a delamination solution; wherein the packaging material comprises ametal and a coating layer coated on one side or both sides of the metal,wherein the coating layer comprises a copolymeric binder.

The coating layer can comprise metal, plastic, paper or possiblycardboard. The metal and the coating layer are separated from each otherby treating the packaging material with a strong base-containingdelamination solution. The method disclosed herein could be utilized indelaminating a wide range of packaging materials, particularly in foodpackaging and beverage packaging, to bring about the recovery andrecycling of individual material components used in packaging.

The following examples are presented to exemplify embodiments of theinvention but are not intended to limit the invention to the specificembodiments set forth. Unless indicated to the contrary, all parts andpercentages are by weight. All numerical values are approximate. Whennumerical ranges are given, it should be understood that embodimentsoutside the stated ranges may still fall within the scope of theinvention. Specific details described in each example should not beconstrued as necessary features of the invention.

EXAMPLES

The pH values of the electrode-delamination solution mixture followingdelamination were measured by an electrode-type pH meter (ION 2700,Eutech Instruments).

The recovery rate refers to the proportion of the sum of the weight ofthe recovered electrode layer and current collector, based on theinitial weight of electrode before immersion into the delaminationsolution.

The delamination success rate refers to the extent of delamination ofelectrode layer from the current collector. It can be calculated by theformula

${{success}{{rate}{}(\%)}} = {\frac{{mass}{of}{electrode}{layer}{successfully}{delaminated}}{\begin{matrix}{{{mass}{of}{electrode}{layer}{successfully}{delaminated}} +} \\{{mass}{of}{electrode}{layer}{remaining}{on}{current}{collector}}\end{matrix}} \times 100\%}$

Accordingly, following the completion or abortion of the delaminationreaction, electrode layer present in the delamination solution wasrecovered to obtain the mass of electrode layer successfullydelaminated, while the remaining electrode layer material (if any) onthe electrode was scraped off manually to obtain the mass of electrodelayer remaining on current collector.

The adhesive strengths of the dried binder layers were measured by atensile testing machine (DZ-106A, obtained from Dongguan Zonhow TestEquipment Co. Ltd., China). This test measures the average forcerequired to peel a binder layer from the current collector at 180° anglein Newtons. The mean roughness depth (Rz) of the current collector is 2μm. The copolymeric binder was coated on the current collector and driedto obtain a binder layer of thickness 10 μm to 12 μm. The coated currentcollector was then placed in an environment of constant temperature of25° C. and humidity of 50% to 60% for 30 minutes. A strip of adhesiontape (3M; US; model no. 810) with a width of 18 mm and a length of 20 mmwas attached onto the surface of the binder layer. The binder strip wasclipped onto the testing machine and the tape was folded back on itselfat 180 degrees, and placed in a moveable jaw and pulled at roomtemperature and a peel rate of 300 mm per minute. The maximum strippingforce measured was taken as the adhesive strength. Measurements wererepeated three times to find the average value.

The peeling strengths of the dried electrode layers were measured by atensile testing machine (DZ-106A, obtained from Dongguan Zonhow TestEquipment Co. Ltd., China). This test measures the average forcerequired to peel an electrode layer from the current collector at 180°angle in Newtons. The mean roughness depth (Rz) of the current collectoris 2 μm. A strip of adhesion tape (3M; US; model no. 810) with a widthof 18 mm and a length of 20 mm was attached onto the surface of thecathode electrode layer. The cathode strip was clipped onto the testingmachine and the tape was folded back on itself at 180 degrees, andplaced in a moveable jaw and pulled at room temperature and a peel rateof 200 mm per minute. The maximum stripping force measured was taken asthe peeling strength. Measurements were repeated three times to find theaverage value.

Example 1 Assembling of Pouch-Type Full Lithium-Ion Batteries A)Preparation of Polymeric Binder

7.45 g of sodium hydroxide (NaOH) was added into a round-bottom flaskcontaining 380 g of distilled water. The mixture was stirred at 80 rpmfor 30 mins to obtain a first suspension.

16.77 g of acrylic acid was added into the first suspension. The mixturewas further stirred at 80 rpm for 30 mins to obtain a second suspension.

7.19 g of acrylamide was dissolved in 10 g of DI water to form anacrylamide solution. Thereafter, 17.19 g of acrylamide solution wasadded into the second suspension. The mixture was further heated to 55°C. and stirred at 80 rpm for 45 mins to obtain a third suspension.

35.95 g of acrylonitrile was added into the third suspension. Themixture was further stirred at 80 rpm for 10 mins to obtain a fourthsuspension.

Further, 0.015 g of water-soluble free radical initiator (ammoniumpersulfate, APS; obtained from Aladdin Industries Corporation, China)was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodiumbisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China)was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 gof sodium bisulfite solution were added into the fourth suspension. Themixture was stirred at 200 rpm for 24 h at 55° C. to obtain a fifthsuspension.

After the complete reaction, the temperature of the fifth suspension waslowered to 25° C. 3.72 g of NaOH was dissolved in 400 g of DI water.Thereafter, 403.72 g of sodium hydroxide solution was added dropwiseinto the fifth suspension to adjust pH to 7.3 to form the sixthsuspension. The sixth suspension was filtered using 200 μm nylon mesh toform the binder material. The solid content of the binder material was8.88 wt.%. The adhesive strength between the copolymeric binder and thecurrent collector was 3.41 N/cm. The components of the copolymericbinder of Example 1 and their respective proportions are shown in Table1 below.

B) Preparation of Positive Electrode

A first mixture was prepared by dispersing 12 g of conductive agent(SuperP; obtained from Timcal Ltd, Bodio, Switzerland) and 100 g ofbinder material (8.88 wt.% solid content) in 74 g of deionized waterwhile stirring with an overhead stirrer (R20, IKA). After the addition,the first mixture was further stirred for about 30 minutes at 25° C. ata speed of 1,200 rpm.

Thereafter, a second mixture was prepared by adding 276 g of NMC532(obtained from Shandong Tianjiao New Energy Co., Ltd, China) in thefirst mixture at 25° C. while stirring with an overhead stirrer. Then,the second mixture was degassed under a pressure of about 10 kPa for 1hour. Then, the second mixture was further stirred for about 60 minutesat 25° C. at a speed of 1,200 rpm to form a homogenized cathode slurry.

The homogenized cathode slurry was coated onto both sides of an aluminumfoil having a thickness of 16 μm as a current collector using a doctorblade coater with a gap width of 120 μm. The coated slurry of 80 μm onthe aluminum foil was dried to form a cathode electrode layer by anelectrically heated oven at 85° C. The drying time was about 120minutes. The electrode was then pressed to decrease the thickness of acathode electrode layer to 34 μm. The surface density of the cathodeelectrode layer on the current collector was 16.00 mg/cm².

C) Preparation of Negative Electrode

A negative electrode slurry was prepared by mixing 93 wt. % of graphite(BTR New Energy Materials Inc., Shenzhen, Guangdong, China) with 1 wt. %carboxymethyl cellulose (CMC, BSH-12, DKS Co. Ltd., Japan) and 3 wt.%SBR (AL-2001, NIPPON A&L INC., Japan) as a binder, and 3 wt. % carbonblack as a conductive agent in deionized water. The solid content of theanode slurry was 51.5 wt. %. The slurry was coated onto both sides of acopper foil having a thickness of 8 μm using a doctor blade coater witha gap width of about 120 μm. The coated slurry on the copper foil wasdried at about 85° C. for 120 minutes by a hot air dryer to obtain anegative electrode. The electrode was then pressed to decrease thethickness of an anode electrode layer to 60 μm and the surface densityof the anode electrode layer was 10 mg/cm².

D) Assembling of Pouched-Type Batteries

After drying, the resulting cathode coating and anode coating were usedto prepare the cathode sheet and anode sheet respectively by cuttinginto pieces of rectangular shape in the size of 5.2 cm×8.5 cm and 5.4cm×8.7 cm correspondingly. Pouch-type batteries were prepared bystacking the cathode and anode sheets in an alternating manner andseparated by porous polyethylene separators (Celgard, LLC, US) having athickness of 25 μm. The electrolyte was a solution of LiPF₆ (1 M) in amixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC) anddimethyl carbonate (DMC) in a volume ratio of 1:1:1. The cells wereassembled in high-purity argon atmosphere with moisture and oxygencontent <1 ppm. After electrolyte filling, the pouch cells were vacuumsealed and then mechanically pressed using a punch tooling with standardshape.

The assembled pouch-type batteries were then subjected to repeatedcharge and discharge cycles at a constant current rate of 1 C between3.0 V and 4.2 V to mimic the real-life usage patterns. The actual cellcapacity was about 5 Ah. The nominal capacity fell below 80% of itsinitial rated capacity after 800 cycles.

Recycling of Batteries A) Discharging and Disassembling of Pouched-TypeBatteries

Used lithium-ion batteries (0.5 kg) were fully discharged by soaking in6% NaCl solution for 12 hours. After discharging, the lithium-ionbatteries were mechanically disassembled using a cutter to recover theelectrodes. Electrodes were cut into smaller pieces having an averagelength of from about 2 cm to about 4 cm.

B) Preparation of Delamination Solution

14.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 0.35 M.

C) Immersion of Cathode in Delamination Solution

5.07 g of cathode was placed in a vessel containing 1000 g of thedelamination solution heated to 25° C. The cathode layer was detachedfrom the aluminum foil. Once the cathode layer was observed to have beendelaminated, the delamination solution comprising sodium hydroxide andDI water was removed by passing through a sieve having a mesh width of 4mm to recover the cathode layer and the aluminum foil. The delaminationsolution could be further reused for delaminating electrodes. Therecovered cathode layer and the aluminum foil were dried in an oven for5 hours at 80° C. under atmospheric pressure and obtained a recoveryrate of 99.40%. The delamination success rate and recovery rate of thecathode materials after delamination were measured and is shown in Table1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Examples 2-5

Pouch-type lithium-ion batteries were prepared by the method describedin Example 1. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 1.

Recycling of Batteries of Example 2 A) Discharging and Disassembling ofPouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 1.

B) Preparation of Delamination Solution

20.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 0.50 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 1, except the above delamination solution was used. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Recycling of Batteries of Example 3 A) Discharging and Disassembling ofPouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 1.

B) Preparation of Delamination Solution

30.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 0.75 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 1, except the above delamination solution was used. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Recycling of Batteries of Example 4 A) Discharging and Disassembling ofPouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 1.

B) Preparation of Delamination Solution

40.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 1.0 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 1, except the above delamination solution was used. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Recycling of Batteries of Example 5 A) Discharging and Disassembling ofPouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 1.

B) Preparation of Delamination Solution

80.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 2.0 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 1, except the above delamination solution was used. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Examples 6-7

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 4.

Recycling of Batteries of Example 6

Recycling of batteries was performed in the same manner as in Example 4,except that delamination solution was heated to 70° C. The delaminationsuccess rate and recovery rate of the cathode materials afterdelamination were measured and is shown in Table 1 below.

Recycling of Batteries of Example 7

Recycling of batteries was performed in the same manner as in Example 4,except that the delamination solution was heated to 90° C. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Preparation of Polymeric Binder of Example 8

8.25 g of sodium hydroxide (NaOH) was added into a round-bottom flaskcontaining 380 g of distilled water. The mixture was stirred at 80 rpmfor 30 mins to obtain a first suspension.

18.22 g of acrylic acid was added into the first suspension. The mixturewas further stirred at 80 rpm for 30 mins to obtain a second suspension.

5.75 g of acrylamide was dissolved in 10 g of DI water to form anacrylamide solution. Thereafter, 15.75 g of acrylamide solution wasadded into the second suspension. The mixture was further heated to 55°C. and stirred at 80 rpm for 45 mins to obtain a third suspension.

35.96 g of acrylonitrile was added into the third suspension. Themixture was further stirred at 80 rpm for 10 mins to obtain a fourthsuspension.

Further, 0.015 g of water-soluble free radical initiator (ammoniumpersulfate, APS; obtained from Aladdin Industries Corporation, China)was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodiumbisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China)was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 gof sodium bisulfite solution were added into the fourth suspension. Themixture was stirred at 200 rpm for 24 h at 55° C. to obtain a fifthsuspension.

After the complete reaction, the temperature of the fifth suspension waslowered to 25° C. 3.72 g of NaOH was dissolved in 400 g of DI water.Thereafter, 403.72 g of sodium hydroxide solution was added dropwiseinto the fifth suspension to adjust pH to 7.3 to form the sixthsuspension. The sixth suspension was filtered using 200 μm nylon mesh toform the binder material. The components of the copolymeric binder ofExample 8 and their respective proportions are shown in Table 1 below.

Preparation of Polymeric Binder of Example 9

5.42 g of sodium hydroxide (NaOH) was added into a round-bottom flaskcontaining 380 g of distilled water. The mixture was stirred at 80 rpmfor 30 mins to obtain a first suspension.

13.12 g of acrylic acid was added into the first suspension. The mixturewas further stirred at 80 rpm for 30 mins to obtain a second suspension.

12.94 g of acrylamide was dissolved in 10 g of DI water to form anacrylamide solution. Thereafter, 22.94 g of acrylamide solution wasadded into the second suspension. The mixture was further heated to 55°C. and stirred at 80 rpm for 45 mins to obtain a third suspension.

34.35 g of acrylonitrile was added into the third suspension. Themixture was further stirred at 80 rpm for 10 mins to obtain a fourthsuspension.

Further, 0.015 g of water-soluble free radical initiator (ammoniumpersulfate, APS; obtained from Aladdin Industries Corporation, China)was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodiumbisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China)was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 gof sodium bisulfite solution were added into the fourth suspension. Themixture was stirred at 200 rpm for 24 h at 55° C. to obtain a fifthsuspension.

After the complete reaction, the temperature of the fifth suspension waslowered to 25° C. 3.72 g of NaOH was dissolved in 400 g of DI water.Thereafter, 403.72 g of sodium hydroxide solution was added dropwiseinto the fifth suspension to adjust pH to 7.3 to form the sixthsuspension. The sixth suspension was filtered using 200 μm nylon mesh toform the binder material. The components of the copolymeric binder ofExample 9 and their respective proportions are shown in Table 1 below.

Preparation of Polymeric Binder of Example 10

9.07 g of sodium hydroxide (NaOH) was added into a round-bottom flaskcontaining 380 g of distilled water. The mixture was stirred at 80 rpmfor 30 mins to obtain a first suspension.

19.68 g of acrylic acid was added into the first suspension. The mixturewas further stirred at 80 rpm for 30 mins to obtain a second suspension.

12.94 g of acrylamide was dissolved in 10 g of DI water to form anacrylamide solution. Thereafter, 22.94 g of acrylamide solution wasadded into the second suspension. The mixture was further heated to 55°C. and stirred at 80 rpm for 45 mins to obtain a third suspension.

29.52 g of acrylonitrile was added into the third suspension. Themixture was further stirred at 80 rpm for 10 mins to obtain a fourthsuspension.

Further, 0.015 g of water-soluble free radical initiator (ammoniumpersulfate, APS; obtained from Aladdin Industries Corporation, China)was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodiumbisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China)was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 gof sodium bisulfite solution were added into the fourth suspension. Themixture was stirred at 200 rpm for 24 h at 55° C. to obtain a fifthsuspension.

After the complete reaction, the temperature of the fifth suspension waslowered to 25° C. 3.72 g of NaOH was dissolved in 400 g of DI water.Thereafter, 403.72 g of sodium hydroxide solution was added dropwiseinto the fifth suspension to adjust pH to 7.3 to form the sixthsuspension. The sixth suspension was filtered using 200 μm nylon mesh toform the binder material. The components of the copolymeric binder ofExample 10 and their respective proportions are shown in Table 1 below.

Preparation of Polymeric Binder of Example 11

6.23 g of sodium hydroxide (NaOH) was added into a round-bottom flaskcontaining 380 g of distilled water. The mixture was stirred at 80 rpmfor 30 mins to obtain a first suspension.

14.58 g of acrylic acid was added into the first suspension. The mixturewas further stirred at 80 rpm for 30 mins to obtain a second suspension.

5.75 g of acrylamide was dissolved in 10 g of DI water to form anacrylamide solution. Thereafter, 15.75 g of acrylamide solution wasadded into the second suspension. The mixture was further heated to 55°C. and stirred at 80 rpm for 45 mins to obtain a third suspension.

38.64 g of acrylonitrile was added into the third suspension. Themixture was further stirred at 80 rpm for 10 mins to obtain a fourthsuspension.

Further, 0.015 g of water-soluble free radical initiator (ammoniumpersulfate, APS; obtained from Aladdin Industries Corporation, China)was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodiumbisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China)was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 gof sodium bisulfite solution were added into the fourth suspension. Themixture was stirred at 200 rpm for 24 h at 55° C. to obtain a fifthsuspension.

After the complete reaction, the temperature of the fifth suspension waslowered to 25° C. 3.72 g of NaOH was dissolved in 400 g of DI water.Thereafter, 403.72 g of sodium hydroxide solution was added dropwiseinto the fifth suspension to adjust pH to 7.3 to form the sixthsuspension. The sixth suspension was filtered using 200 μm nylon mesh toform the binder material. The components of the copolymeric binder ofExample 11 and their respective proportions are shown in Table 1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Examples 8-11 A)Preparation of Positive Electrodes

The positive electrodes were prepared by the method described in Example4, except the binder materials prepared for Examples 8-11 were eachindividually used to produce the cathodes of Examples 8-11 respectively.

B) Preparation of Negative Electrodes

The negative electrodes were prepared by the method described in Example4.

C) Assembling of Pouched-Type Batteries

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 4.

Recycling of Batteries of Examples 8-11

Recycling of batteries was performed in the same manner as in Example 4.The delamination success rates and recovery rates of the cathodematerials after delamination were measured and is shown in Table 1below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Example 12

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 4.

Recycling of Batteries of Example 12 A) Discharging and Disassembling ofPouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 4.

B) Preparation of Delamination Solution

56.1 g of anhydrous potassium hydroxide (Sigma-Aldrich, USA) was addedto 1000 g of DI water to form a delamination solution with aconcentration of 1.0 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 4, except the above delamination solution was used. Thedelamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Example 13

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4, except that 276 g of NMC532 was replaced with LCO of thesame weight. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 4.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Example 14

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4, except that 276 g of NMC532 was replaced with LFP (TianjinSitelan Energy Technology Co. Ltd., China) of the same weight. Theassembled pouch-type batteries were then subjected to repeated cyclingin the same manner as in Example 4.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Example 15

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4, except that in the preparation of the polymeric binder,16.77 g of acrylic acid was replaced with 23.30 g of 2-ethylacrylic acidin the preparation of the second suspension. The assembled pouch-typebatteries were then subjected to repeated cycling in the same manner asin Example 4.

Assembling of Pouch-Type Full Lithium-Ion Batteries of Example 16

Pouch-type lithium-ion batteries were prepared by the method describedin Example 4, except that in the preparation of the polymeric binder,16.77 g of acrylic acid was replaced with 25.16 g of vinylsulfonic acidin the preparation of the second suspension. The assembled pouch-typebatteries were then subjected to repeated cycling in the same manner asin Example 4.

Recycling of Batteries of Examples 13-16

Recycling of batteries was performed in the same manner as in Example 4.The delamination success rates and recovery rates of the cathodematerials after delamination were measured and is shown in Table 1below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 1 A) Preparation of Positive Electrode

A first suspension was prepared by dispersing 10 g of polyvinylidenefluoride, PVDF (Solef® 5130, obtained from Solvay S.A., Belgium) as thepolymeric binder in 250 g of NMP (>99%, Sigma-Aldrich, USA) in a 500 mLround bottom flask while stirring with an overhead stirrer at 500 rpmfor about 3 hours.

Thereafter, 15 g of SuperP was added into the first suspension andstirred at 1,200 rpm for 30 minutes to obtain the second suspension.

A third suspension was prepared by dispersing 225 g of NMC532 into thesecond suspension at 25° C. while stirring with an overhead stirrer.Then, the third suspension was degassed under a pressure of about 10 kPafor 1 hour. The third suspension was further stirred for about 90minutes at 25° C. at a speed of 1,200 rpm to form a homogenized cathodeslurry.

The homogenized cathode slurry was coated onto both sides of an aluminumfoil having a thickness of 16 μm as a current collector using a doctorblade coater with a gap width of 120 μm. The coated slurry of 80 μm onthe aluminum foil was dried to form a cathode electrode layer by anelectrically heated oven at 85° C. The drying time was about 120minutes. The electrode was then pressed to decrease the thickness of thecathode electrode layer to 34 μm.

B) Preparation of Negative Electrode

The negative electrode was prepared in the same manner as in Example 2.

C) Assembling of Pouched-Type Batteries

The pouch-type batteries were assembled in the same manner as in Example2. The assembled pouch-type batteries were then subjected to repeatedcycling in the same manner as in Example 2.

Recycling of Batteries of Comparative Example 1

Recycling of batteries was performed in the same manner as in Example 2,except if delamination was not complete, the reaction was aborted after5 minutes. The delamination success rate and recovery rate of thecathode materials after delamination were measured and is shown in Table1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 2

Pouch-type lithium-ion batteries were prepared by the method describedin Example 1. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 1.

Recycling of Batteries of Comparative Example 2

Recycling of batteries was performed in the same manner as in Example 1,except that delamination agent was not added and only 1000 g of DI waterwas added in the preparation of the delamination solution. Ifdelamination was not complete, the reaction was aborted after 5 minutes.The delamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 3

Pouch-type lithium-ion batteries were prepared by the method describedin Example 1. The assembled pouch-type batteries were then subjected torepeated cycling in the same manner as in Example 1.

Recycling of Batteries of Comparative Example 3 A) Discharging andDisassembling of Pouched-Type Batteries

Used lithium-ion batteries were discharged and disassembled by the samemethod described in Example 1.

B) Preparation of Delamination Solution

4.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to1000 g of DI water to form a delamination solution with a concentrationof 0.10 M.

C) Immersion of Cathode in Delamination Solution

Cathodes were immersed and delaminated by the method described inExample 1, except the above delamination solution was used. Ifdelamination was not complete, the reaction was aborted after 5 minutes.The delamination success rate and recovery rate of the cathode materialsafter delamination were measured and is shown in Table 1 below.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 4

Pouch-type lithium-ion batteries were prepared by the method describedin Example 2, except that in the preparation of polymeric binder, 9.47 gof sodium hydroxide was added in the preparation of the firstsuspension, 20.41 g of acrylic acid was added in the preparation of thesecond suspension, acrylamide was not added in the preparation of thethird suspension and 38.64 g of acrylonitrile was added in thepreparation of the fourth suspension. The assembled pouch-type batterieswere then subjected to repeated cycling in the same manner as in Example2.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 5

Pouch-type lithium-ion batteries were prepared by the method describedin Example 2, except that in the preparation of polymeric binder, 2.19 gof sodium hydroxide was added in the preparation of the firstsuspension, 7.29 g of acrylic acid was added in the preparation of thesecond suspension, 12.94 g of acrylamide was added in the preparation ofthe third suspension and 38.64 g of acrylonitrile was added in thepreparation of the fourth suspension. The assembled pouch-type batterieswere then subjected to repeated cycling in the same manner as in Example2.

Assembling of Pouch-Type Full Lithium-Ion Batteries of ComparativeExample 6

Pouch-type lithium-ion batteries were prepared by the method describedin Example 2, except that in the preparation of polymeric binder, 4.21 gof sodium hydroxide was added in the preparation of the firstsuspension, 10.93 g of acrylic acid was added in the preparation of thesecond suspension, 25.16 g of acrylamide was added in the preparation ofthe third suspension and 26.84 g of acrylonitrile was added in thepreparation of the fourth suspension. The assembled pouch-type batterieswere then subjected to repeated cycling in the same manner as in Example2.

Recycling of Batteries of Comparative Examples 4-6

Recycling of batteries was performed in the same manner as in Example 2,except if delamination was not complete, the reaction was aborted after5 minutes. The delamination success rates and recovery rates of thecathode materials after delamination were measured and is shown in Table1 below.

TABLE 1 Structural units in the copolymer Proportion of Proportion ofProportion of Delamination solution structural structural structuralCathode Delamination agent Delamination Recovery Time unit (a) unit (b)unit (c) active Aqueous Concentration success rate rate taken (mol %)(mol %) (mol %) material solvent Type (M) (%) (%) (s) Example 1 23.0110.00 66.99 NCM532 Water NaOH 0.35 77 99.40 120 Example 2 23.01 10.0066.99 NCM532 Water NaOH 0.50 88 99.00 120 Example 3 23.01 10.00 66.99NCM532 Water NaOH 0.75 92 99.20 120 Example 4 23.01 10.00 66.99 NCM532Water NaOH 1.0 100 99.20 30 Example 5 23.01 10.00 66.99 NCM532 WaterNaOH 2.0 100 99.00 30 Example 6 23.01 10.00 66.99 NCM532 Water NaOH 1.0100 98.00 30 Example 7 23.01 10.00 66.99 NCM532 Water NaOH 1.0 100 97.4030 Example 8 25.00 8.00 67.00 NCM532 Water NaOH 1.0 100 98.40 30 Example9 18.00 18.00 64.00 NCM532 Water NaOH 1.0 100 98.60 30 Example 10 27.0018.00 55.00 NCM532 Water NaOH 1.0 100 98.80 30 Example 11 20.00 8.0072.00 NCM532 Water NaOH 1.0 100 99.00 30 Example 12 23.01 10.00 66.99NCM532 Water KOH 1.0 100 98.80 30 Example 13 23.01 10.00 66.99 LCO WaterNaOH 1.0 100 98.20 30 Example 14 23.01 10.00 66.99 LFP Water NaOH 1.0100 98.40 30 Example 15 23.01 10.00 66.99 NCM532 Water NaOH 1.0 10099.00 30 Example 16 23.01 10.00 66.99 NCM532 Water NaOH 1.0 100 98.80 30Comparative 0.00 0.00 0.00 NCM532 Water NaOH 0.5 15 —^(#) 300 Example 1*Comparative 23.01 10.00 66.99 NCM532 Water — — 4 —^(#) 300 Example 2Comparative 23.01 10.00 66.99 NCM532 Water NaOH 0.1 6 —^(#) 300 Example3 Comparative 28.00 0.00 72.00 NCM532 Water NaOH 0.5 18 —^(#) 300Example 4 Comparative 10.00 18.00 72.00 NCM532 Water NaOH 0.5 25 —^(#)300 Example 5 Comparative 15.00 35.00 50.00 NCM532 Water NaOH 0.5 28—^(#) 300 Example 6 *PVDF was used as the binder instead. ^(#)As successrate was under 75%, recovery rate was not calculated.

While the invention has been described with respect to a limited numberof embodiments, the specific features of one embodiment should not beattributed to other embodiments of the invention. In some embodiments,the methods may include numerous steps not mentioned herein. In otherembodiments, the methods do not include, or are substantially free of,any steps not enumerated herein. Variations and modifications from thedescribed embodiments exist. The appended claims intend to cover allthose modifications and variations as falling within the scope of theinvention.

1. A method for delaminating a composite by immersing the composite intoa delamination solution; wherein the composite comprises a metalsubstrate and a coating applied on one side or both sides of the metalsubstrate, wherein the coating comprises a copolymeric binder; whereinthe copolymeric binder comprises a structural unit (a), derived from amonomer selected from the group consisting of a carboxylic acidgroup-containing monomer, a sulfonic acid group-containing monomer, aphosphonic acid group-containing monomer, a carboxylic acid saltgroup-containing monomer, a sulfonic acid salt group-containing monomer,a phosphonic acid salt group-containing monomer, and combinationsthereof.
 2. The method of claim 1, wherein the delamination solutioncomprises a delamination agent and an aqueous solvent; and wherein theconcentration of the delamination agent in the delamination solution isfrom about 0.3 to 3 M.
 3. The method of claim 2, wherein thedelamination agent is selected from the group consisting of lithiumhydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide,cesium hydroxide, calcium hydroxide, strontium hydroxide, bariumhydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide,cesium oxide, calcium oxide, strontium oxide, barium oxide, andcombinations thereof.
 4. The method of claim 2, wherein the aqueoussolvent is water.
 5. The method of claim 2, wherein the aqueoussolutionsolvent comprises water as the major component and a minorcomponent, wherein the proportion of water in the aqueous solvent isgreater than 51% and less than 100% by weight; and wherein the minorcomponent is selected from the group consisting of methanol, ethanol,isopropanol, n-propanol, tert-butanol, n-butanol, acetone, dimethylketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propylacetate, butyl acetate, and combinations thereof.
 6. The method of claim1, wherein the proportion of structural unit (a) within thecopolymercopolymeric binder is from about 15% to about 30% by mole,based on the total number of moles of monomeric units in the copolymericbinder.
 7. The method of claim 1, wherein the carboxylic acidgroup-containing monomer is selected from the group consisting ofacrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid,cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconicacid, itaconic anhydride, tetraconic acid, 2-ethylacrylic acid,isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelicacid, tiglic acid, 3,3-dimethyl acrylic acid, 3-propyl acrylic acid,trans-2-methyl-3-ethyl acrylic acid, cis-2-methyl-3-ethyl acrylic acid,3-isopropyl acrylic acid, trans-3-methyl-3-ethyl acrylic acid,cis-3-methyl-3-ethyl acrylic acid, 2-isopropyl acrylic acid, trimethylacrylic acid, 2-methyl-3,3-diethyl acrylic acid, 3-butyl acrylic acid,2-butyl acrylic acid, 2-pentyl acrylic acid, 2-methyl-2-hexenoic acid,trans-3-methyl-2-hexenoic acid, 3-methyl-3-propyl acrylic acid,2-ethyl-3-propyl acrylic acid, 2,3-diethyl acrylic acid, 3,3-diethylacrylic acid, 3-methyl-3-hexyl acrylic acid, 3-methyl-3-tert-butylacrylic acid, 2-methyl-3-pentyl acrylic acid, 3-methyl-3-pentyl acrylicacid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid,3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butyl acrylic acid,2,3-dimethyl-3-ethyl acrylic acid, 3,3-dimethyl-2-ethyl acrylic acid,3-methyl-3-isopropyl acrylic acid, 2-methyl-3-isopropyl acrylic acid,trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid,α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid,α-chloro-β-E-methoxyacrylic acid, methyl maleic acid, dimethyl maleicacid, phenyl maleic acid, bromo maleic acid, chloromaleic acid,dichloromaleic acid, fluoromaleic acid, difluoro maleic acid, nonylhydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate,octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleicanhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylicanhydride, methacrylic anhydride, methacrolein, methacryloyl chloride,methacryloyl fluoride, methacryloyl bromide, and combinations thereof.8. The method of claim 1, wherein the carboxylic acid saltgroup-containing monomer is selected from the group consisting ofacrylic acid salt, methacrylic acid salt, crotonic acid salt, 2-butylcrotonic acid salt, cinnamic acid salt, maleic acid salt, maleicanhydride salt, fumaric acid salt, itaconic acid salt, itaconicanhydride salt, tetraconic acid salt, 2-ethylacrylic acid salt,isocrotonic acid salt, cis-2-pentenoic acid salt, trans-2-pentenoic acidsalt, angelic acid salt, tiglic acid salt, 3,3-dimethyl acrylic acidsalt, 3-propyl acrylic acid salt, trans-2-methyl-3-ethyl acrylic acidsalt, cis-2-methyl-3-ethyl acrylic acid salt, 3-isopropyl acrylic acidsalt, trans-3-methyl-3-ethyl acrylic acid salt, cis-3-methyl-3-ethylacrylic acid salt, 2-isopropyl acrylic acid salt, trimethyl acrylic acidsalt, 2-methyl-3,3-diethyl acrylic acid salt, 3-butyl acrylic acid salt,2-butyl acrylic acid salt, 2-pentyl acrylic acid salt,2-methyl-2-hexenoic acid salt, trans-3-methyl-2-hexenoic acid salt,3-methyl-3-propyl acrylic acid salt, 2-ethyl-3-propyl acrylic acid salt,2,3-diethyl acrylic acid salt, 3,3-diethyl acrylic acid salt,3-methyl-3-hexyl acrylic acid salt, 3-methyl-3-tert-butyl acrylic acidsalt, 2-methyl-3-pentyl acrylic acid salt, 3-methyl-3-pentyl acrylicacid salt, 4-methyl-2-hexenoic acid salt, 4-ethyl-2-hexenoic acid salt,3-methyl-2-ethyl-2-hexenoic acid salt, 3-tert-butyl acrylic acid salt,2,3-dimethyl-3-ethyl acrylic acid salt, 3,3-dimethyl-2-ethyl acrylicacid salt, 3-methyl-3-isopropyl acrylic acid salt, 2-methyl-3-isopropylacrylic acid salt, trans-2-octenoic acid salt, cis-2-octenoic acid salt,trans-2-decenoic acid salt, α-acetoxyacrylic acid salt,β-trans-aryloxyacrylic acid salt, α-chloro-β-E-methoxyacrylic acid salt,methyl maleic acid salt, dimethyl maleic acid salt, phenyl maleic acidsalt, bromo maleic acid salt, chloromaleic acid salt, dichloromaleicacid salt, fluoromaleic acid salt, difluoro maleic acid salt, andcombinations thereof.
 9. The method of claim 1, wherein the sulfonicacid group-containing monomer is selected from the group consisting ofvinylsulfonic acid, methylvinylsulfonic acid, allylvinylsulfonic acid,allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid,2-sulfoethyl methacrylic acid, 2-methylprop-2-ene-1-sulfonic acid,2-acrylamido-2-methyl-1-propane sulfonic acid,3-allyloxy-2-hydroxy-1-propane sulfonic acid, allyl hydrogensulfate,vinyl hydrogensulfate, and combinations thereof.
 10. The method of claim1, wherein the sulfonic acid salt group-containing monomer is selectedfrom the group consisting of vinylsulfonic acid salt,methylvinylsulfonic acid salt, allylvinylsulfonic acid salt,allylsulfonic acid salt, methallylsulfonic acid salt, styrenesulfonicacid salt, 2-sulfoethyl methacrylic acid salt,2-methylprop-2-ene-1-sulfonic acid salt, 2-acrylamido-2-methyl-1-propanesulfonic acid salt, 3-allyloxy-2-hydroxy-1-propane sulfonic acid salt,allyl sulfate salt, vinyl sulfate salt, and combinations thereof. 11.The method of claim 1, wherein the phosphonic acid group-containingmonomer is selected from the group consisting of vinyl phosphonic acid,allyl phosphonic acid, vinyl benzyl phosphonic acid, acrylamide alkylphosphonic acid, methacrylamide alkyl phosphonic acid, acrylamide alkyldiphosphonic acid, acryloylphosphonic acid, 2-methacryloyloxyethylphosphonic acid, bis(2-methacryloyloxyethyl) phosphonic acid, ethylene2-methacryloyloxyethyl phosphonic acid, ethyl-methacryloyloxyethylphosphonic acid, allyl hydrogenphosphate, vinyl hydrogenphosphate, andcombinations thereof.
 12. The method of claim 1, wherein the phosphonicacid salt group-containing monomer is selected from the group consistingof vinyl phosphonic acid salt, salt of allyl phosphonic acid, salt ofvinyl benzyl phosphonic acid, salt of acrylamide alkyl phosphonic acid,salt of methacrylamide alkyl phosphonic acid, salt of acrylamide alkyldiphosphonic acid, salt of acryloylphosphonic acid, salt of2-methacryloyloxyethyl phosphonic acid, salt ofbis(2-methacryloyloxyethyl) phosphonic acid, salt of ethylene2-methacryloyloxyethyl phosphonic acid, salt ofethyl-methacryloyloxyethyl phosphonic acid, allyl phosphate salt, vinylphosphate salt, and combinations thereof.
 13. The method of claim 1,wherein the copolymeric binder further comprises a structural unit (b),wherein structural unit (b) is derived from a monomer selected from thegroup consisting of an amide group-containing monomer, a hydroxylgroup-containing monomer, and combinations thereof.
 14. The method ofclaim 13, wherein the proportion of structural unit (b) within thecopolymeric binder is from about 5% to about 20% by mole, based on thetotal number of moles of monomeric units in the copolymeric binder. 15.The method of claim 13, wherein the amide group-containing monomer isselected from the group consisting of acrylamide, methacrylamide,N-methyl methacrylamide, N-ethyl methacrylamide, N-n-propylmethacrylamide, N-isopropyl methacrylamide, isopropyl acrylamide,N-n-butyl methacrylamide, N-isobutyl methacrylamide, N,N-dimethylacrylamide, N,N-dimethyl methacrylamide, N,N-diethyl acrylamide,N,N-diethyl methacrylamide, N-methylol methacrylamide,N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide,N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide,N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylol methacrylamide, diacetone methacrylamide,diacetone acrylamide, methacryloyl morpholine, N-hydroxylmethacrylamide, N-methoxymethyl acrylamide, N-methoxymethylmethacrylamide, N,N′-methylene-bis-acrylamide (MBA), N-hydroxymethylacrylamide, and combinations thereof.
 16. The method of claim 1, whereinthe copolymeric binder further comprises a structural unit (c), whereinstructural unit (c) is derived from a monomer selected from the groupconsisting of a nitrile group-containing monomer, an estergroup-containing monomer, an epoxy group-containing monomer, afluorine-containing monomer, and combinations thereof.
 17. The method ofclaim 16, wherein the proportion of structural unit (c) within thecopolymeric binder is from about 50% to about 75% by mole, based on thetotal number of moles of monomeric units in the copolymeric binder:, andwherein the nitrile group-containing monomer is selected from the groupconsisting of acrylonitrile, α-halogenoacrylonitrile,α-alkylacrylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile,α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile,α-isopropylacrylonitrile, α-n-hexylacrylonitrile,α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile,α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile,α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile,α-(cyanophenyl)acrylonitrile, vinylidene cyanide, and combinationsthereof.
 18. (canceled)
 19. The method of claim 1, wherein the metalsubstrate is in the form of a foil, sheet, film, or combinationsthereof; wherein the metal substrate is selected from the groupconsisting of stainless steel, titanium, nickel, aluminum, copper,platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin,vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.
 20. Themethod of claim 1, wherein the metal substrate is in the form of aporous body having a three-dimensional network structure; wherein themetal substrate is selected from the group consisting of stainlesssteel, titanium, nickel, aluminum, copper, platinum, gold, silver,chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium,iron, cobalt, lead, and alloys thereof.
 21. The method of claim 1,wherein the weight ratio of the composite to the delamination solutionis from about 0.01% to about 50%; and wherein the composite is immersedinto the delamination solution at a temperature of from about 10° C. toabout 90° C.